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  • Migrating IBM ClearCase to TFS

    - by Bob Hardister
    Using the Team Foundation Server Integration Tools Platform. Versions: ClearCase: 7.1.1.2 Team Foundation Server: 2012 RTM Integration Tools: 2.2.20314.1 OS: Windows 2008 R2 ENT SP1 I was able to do a simple example migration of a few files by using the following approach: Using a dynamic view Creating a view shortcut drive (i.e. Z:\) Running the tools as a UI client (not as a windows service) Running the tools UI in user mode (do not “Run as Administrator”) Using the CC detailed history adapter Selecting the view shortcut drive (i.e. Z) on the Tools UI Connect to CC dialog Selecting the “Detect Changes in CC” option on the Tools UI Connect to CC dialog Changing the DisableTargetAnalysis value to True on the Tools UI configuration view I have yet to perform actual migrations for real projects, but will update this blog as I do.

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  • PHP Variable Variable inside []'s

    - by Homer_J
    Hi all, I hope there is a simple solution! I have a variable: $results['q1']; Is it possible to have the 'q1' element as a variable, something like this: $results['$i[question]']; Have not been able to find a solution on Google and researching the PHP manuals... Anyone got a suggestion/ solution? Thanks, Homer.

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  • How to make an unit test always pass?

    - by brain_damage
    Let's assume someone has to write a solution to a problem and I have to test his solution with some tests. Is it possible (maybe with reflections or something) his program to pass all my tests, but to have nothing in common with the real solution to the problem?

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  • 64-bit Archives Needed

    - by user9154181
    A little over a year ago, we received a question from someone who was trying to build software on Solaris. He was getting errors from the ar command when creating an archive. At that time, the ar command on Solaris was a 32-bit command. There was more than 2GB of data, and the ar command was hitting the file size limit for a 32-bit process that doesn't use the largefile APIs. Even in 2011, 2GB is a very large amount of code, so we had not heard this one before. Most of our toolchain was extended to handle 64-bit sized data back in the 1990's, but archives were not changed, presumably because there was no perceived need for it. Since then of course, programs have continued to get larger, and in 2010, the time had finally come to investigate the issue and find a way to provide for larger archives. As part of that process, I had to do a deep dive into the archive format, and also do some Unix archeology. I'm going to record what I learned here, to document what Solaris does, and in the hope that it might help someone else trying to solve the same problem for their platform. Archive Format Details Archives are hardly cutting edge technology. They are still used of course, but their basic form hasn't changed in decades. Other than to fix a bug, which is rare, we don't tend to touch that code much. The archive file format is described in /usr/include/ar.h, and I won't repeat the details here. Instead, here is a rough overview of the archive file format, implemented by System V Release 4 (SVR4) Unix systems such as Solaris: Every archive starts with a "magic number". This is a sequence of 8 characters: "!<arch>\n". The magic number is followed by 1 or more members. A member starts with a fixed header, defined by the ar_hdr structure in/usr/include/ar.h. Immediately following the header comes the data for the member. Members must be padded at the end with newline characters so that they have even length. The requirement to pad members to an even length is a dead giveaway as to the age of the archive format. It tells you that this format dates from the 1970's, and more specifically from the era of 16-bit systems such as the PDP-11 that Unix was originally developed on. A 32-bit system would have required 4 bytes, and 64-bit systems such as we use today would probably have required 8 bytes. 2 byte alignment is a poor choice for ELF object archive members. 32-bit objects require 4 byte alignment, and 64-bit objects require 64-bit alignment. The link-editor uses mmap() to process archives, and if the members have the wrong alignment, we have to slide (copy) them to the correct alignment before we can access the ELF data structures inside. The archive format requires 2 byte padding, but it doesn't prohibit more. The Solaris ar command takes advantage of this, and pads ELF object members to 8 byte boundaries. Anything else is padded to 2 as required by the format. The archive header (ar_hdr) represents all numeric values using an ASCII text representation rather than as binary integers. This means that an archive that contains only text members can be viewed using tools such as cat, more, or a text editor. The original designers of this format clearly thought that archives would be used for many file types, and not just for objects. Things didn't turn out that way of course — nearly all archives contain relocatable objects for a single operating system and machine, and are used primarily as input to the link-editor (ld). Archives can have special members that are created by the ar command rather than being supplied by the user. These special members are all distinguished by having a name that starts with the slash (/) character. This is an unambiguous marker that says that the user could not have supplied it. The reason for this is that regular archive members are given the plain name of the file that was inserted to create them, and any path components are stripped off. Slash is the delimiter character used by Unix to separate path components, and as such cannot occur within a plain file name. The ar command hides the special members from you when you list the contents of an archive, so most users don't know that they exist. There are only two possible special members: A symbol table that maps ELF symbols to the object archive member that provides it, and a string table used to hold member names that exceed 15 characters. The '/' convention for tagging special members provides room for adding more such members should the need arise. As I will discuss below, we took advantage of this fact to add an alternate 64-bit symbol table special member which is used in archives that are larger than 4GB. When an archive contains ELF object members, the ar command builds a special archive member known as the symbol table that maps all ELF symbols in the object to the archive member that provides it. The link-editor uses this symbol table to determine which symbols are provided by the objects in that archive. If an archive has a symbol table, it will always be the first member in the archive, immediately following the magic number. Unlike member headers, symbol tables do use binary integers to represent offsets. These integers are always stored in big-endian format, even on a little endian host such as x86. The archive header (ar_hdr) provides 15 characters for representing the member name. If any member has a name that is longer than this, then the real name is written into a special archive member called the string table, and the member's name field instead contains a slash (/) character followed by a decimal representation of the offset of the real name within the string table. The string table is required to precede all normal archive members, so it will be the second member if the archive contains a symbol table, and the first member otherwise. The archive format is not designed to make finding a given member easy. Such operations move through the archive from front to back examining each member in turn, and run in O(n) time. This would be bad if archives were commonly used in that manner, but in general, they are not. Typically, the ar command is used to build an new archive from scratch, inserting all the objects in one operation, and then the link-editor accesses the members in the archive in constant time by using the offsets provided by the symbol table. Both of these operations are reasonably efficient. However, listing the contents of a large archive with the ar command can be rather slow. Factors That Limit Solaris Archive Size As is often the case, there was more than one limiting factor preventing Solaris archives from growing beyond the 32-bit limits of 2GB (32-bit signed) and 4GB (32-bit unsigned). These limits are listed in the order they are hit as archive size grows, so the earlier ones mask those that follow. The original Solaris archive file format can handle sizes up to 4GB without issue. However, the ar command was delivered as a 32-bit executable that did not use the largefile APIs. As such, the ar command itself could not create a file larger than 2GB. One can solve this by building ar with the largefile APIs which would allow it to reach 4GB, but a simpler and better answer is to deliver a 64-bit ar, which has the ability to scale well past 4GB. Symbol table offsets are stored as 32-bit big-endian binary integers, which limits the maximum archive size to 4GB. To get around this limit requires a different symbol table format, or an extension mechanism to the current one, similar in nature to the way member names longer than 15 characters are handled in member headers. The size field in the archive member header (ar_hdr) is an ASCII string capable of representing a 32-bit unsigned value. This places a 4GB size limit on the size of any individual member in an archive. In considering format extensions to get past these limits, it is important to remember that very few archives will require the ability to scale past 4GB for many years. The old format, while no beauty, continues to be sufficient for its purpose. This argues for a backward compatible fix that allows newer versions of Solaris to produce archives that are compatible with older versions of the system unless the size of the archive exceeds 4GB. Archive Format Differences Among Unix Variants While considering how to extend Solaris archives to scale to 64-bits, I wanted to know how similar archives from other Unix systems are to those produced by Solaris, and whether they had already solved the 64-bit issue. I've successfully moved archives between different Unix systems before with good luck, so I knew that there was some commonality. If it turned out that there was already a viable defacto standard for 64-bit archives, it would obviously be better to adopt that rather than invent something new. The archive file format is not formally standardized. However, the ar command and archive format were part of the original Unix from Bell Labs. Other systems started with that format, extending it in various often incompatible ways, but usually with the same common shared core. Most of these systems use the same magic number to identify their archives, despite the fact that their archives are not always fully compatible with each other. It is often true that archives can be copied between different Unix variants, and if the member names are short enough, the ar command from one system can often read archives produced on another. In practice, it is rare to find an archive containing anything other than objects for a single operating system and machine type. Such an archive is only of use on the type of system that created it, and is only used on that system. This is probably why cross platform compatibility of archives between Unix variants has never been an issue. Otherwise, the use of the same magic number in archives with incompatible formats would be a problem. I was able to find information for a number of Unix variants, described below. These can be divided roughly into three tribes, SVR4 Unix, BSD Unix, and IBM AIX. Solaris is a SVR4 Unix, and its archives are completely compatible with those from the other members of that group (GNU/Linux, HP-UX, and SGI IRIX). AIX AIX is an exception to rule that Unix archive formats are all based on the original Bell labs Unix format. It appears that AIX supports 2 formats (small and big), both of which differ in fundamental ways from other Unix systems: These formats use a different magic number than the standard one used by Solaris and other Unix variants. They include support for removing archive members from a file without reallocating the file, marking dead areas as unused, and reusing them when new archive items are inserted. They have a special table of contents member (File Member Header) which lets you find out everything that's in the archive without having to actually traverse the entire file. Their symbol table members are quite similar to those from other systems though. Their member headers are doubly linked, containing offsets to both the previous and next members. Of the Unix systems described here, AIX has the only format I saw that will have reasonable insert/delete performance for really large archives. Everyone else has O(n) performance, and are going to be slow to use with large archives. BSD BSD has gone through 4 versions of archive format, which are described in their manpage. They use the same member header as SVR4, but their symbol table format is different, and their scheme for long member names puts the name directly after the member header rather than into a string table. GNU/Linux The GNU toolchain uses the SVR4 format, and is compatible with Solaris. HP-UX HP-UX seems to follow the SVR4 model, and is compatible with Solaris. IRIX IRIX has 32 and 64-bit archives. The 32-bit format is the standard SVR4 format, and is compatible with Solaris. The 64-bit format is the same, except that the symbol table uses 64-bit integers. IRIX assumes that an archive contains objects of a single ELFCLASS/MACHINE, and any archive containing ELFCLASS64 objects receives a 64-bit symbol table. Although they only use it for 64-bit objects, nothing in the archive format limits it to ELFCLASS64. It would be perfectly valid to produce a 64-bit symbol table in an archive containing 32-bit objects, text files, or anything else. Tru64 Unix (Digital/Compaq/HP) Tru64 Unix uses a format much like ours, but their symbol table is a hash table, making specific symbol lookup much faster. The Solaris link-editor uses archives by examining the entire symbol table looking for unsatisfied symbols for the link, and not by looking up individual symbols, so there would be no benefit to Solaris from such a hash table. The Tru64 ld must use a different approach in which the hash table pays off for them. Widening the existing SVR4 archive symbol tables rather than inventing something new is the simplest path forward. There is ample precedent for this approach in the ELF world. When ELF was extended to support 64-bit objects, the approach was largely to take the existing data structures, and define 64-bit versions of them. We called the old set ELF32, and the new set ELF64. My guess is that there was no need to widen the archive format at that time, but had there been, it seems obvious that this is how it would have been done. The Implementation of 64-bit Solaris Archives As mentioned earlier, there was no desire to improve the fundamental nature of archives. They have always had O(n) insert/delete behavior, and for the most part it hasn't mattered. AIX made efforts to improve this, but those efforts did not find widespread adoption. For the purposes of link-editing, which is essentially the only thing that archives are used for, the existing format is adequate, and issues of backward compatibility trump the desire to do something technically better. Widening the existing symbol table format to 64-bits is therefore the obvious way to proceed. For Solaris 11, I implemented that, and I also updated the ar command so that a 64-bit version is run by default. This eliminates the 2 most significant limits to archive size, leaving only the limit on an individual archive member. We only generate a 64-bit symbol table if the archive exceeds 4GB, or when the new -S option to the ar command is used. This maximizes backward compatibility, as an archive produced by Solaris 11 is highly likely to be less than 4GB in size, and will therefore employ the same format understood by older versions of the system. The main reason for the existence of the -S option is to allow us to test the 64-bit format without having to construct huge archives to do so. I don't believe it will find much use outside of that. Other than the new ability to create and use extremely large archives, this change is largely invisible to the end user. When reading an archive, the ar command will transparently accept either form of symbol table. Similarly, the ELF library (libelf) has been updated to understand either format. Users of libelf (such as the link-editor ld) do not need to be modified to use the new format, because these changes are encapsulated behind the existing functions provided by libelf. As mentioned above, this work did not lift the limit on the maximum size of an individual archive member. That limit remains fixed at 4GB for now. This is not because we think objects will never get that large, for the history of computing says otherwise. Rather, this is based on an estimation that single relocatable objects of that size will not appear for a decade or two. A lot can change in that time, and it is better not to overengineer things by writing code that will sit and rot for years without being used. It is not too soon however to have a plan for that eventuality. When the time comes when this limit needs to be lifted, I believe that there is a simple solution that is consistent with the existing format. The archive member header size field is an ASCII string, like the name, and as such, the overflow scheme used for long names can also be used to handle the size. The size string would be placed into the archive string table, and its offset in the string table would then be written into the archive header size field using the same format "/ddd" used for overflowed names.

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  • MySQL Syslog Audit Plugin

    - by jonathonc
    This post shows the construction process of the Syslog Audit plugin that was presented at MySQL Connect 2012. It is based on an environment that has the appropriate development tools enabled including gcc,g++ and cmake. It also assumes you have downloaded the MySQL source code (5.5.16 or higher) and have compiled and installed the system into the /usr/local/mysql directory ready for use.  The information provided below is designed to show the different components that make up a plugin, and specifically an audit type plugin, and how it comes together to be used within the MySQL service. The MySQL Reference Manual contains information regarding the plugin API and how it can be used, so please refer there for more detailed information. The code in this post is designed to give the simplest information necessary, so handling every return code, managing race conditions etc is not part of this example code. Let's start by looking at the most basic implementation of our plugin code as seen below: /*    Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.    Author:  Jonathon Coombes    Licence: GPL    Description: An auditing plugin that logs to syslog and                 can adjust the loglevel via the system variables. */ #include <stdio.h> #include <string.h> #include <mysql/plugin_audit.h> #include <syslog.h> There is a commented header detailing copyright/licencing and meta-data information and then the include headers. The two important include statements for our plugin are the syslog.h plugin, which gives us the structures for syslog, and the plugin_audit.h include which has details regarding the audit specific plugin api. Note that we do not need to include the general plugin header plugin.h, as this is done within the plugin_audit.h file already. To implement our plugin within the current implementation we need to add it into our source code and compile. > cd /usr/local/src/mysql-5.5.28/plugin > mkdir audit_syslog > cd audit_syslog A simple CMakeLists.txt file is created to manage the plugin compilation: MYSQL_ADD_PLUGIN(audit_syslog audit_syslog.cc MODULE_ONLY) Run the cmake  command at the top level of the source and then you can compile the plugin using the 'make' command. This results in a compiled audit_syslog.so library, but currently it is not much use to MySQL as there is no level of api defined to communicate with the MySQL service. Now we need to define the general plugin structure that enables MySQL to recognise the library as a plugin and be able to install/uninstall it and have it show up in the system. The structure is defined in the plugin.h file in the MySQL source code.  /*   Plugin library descriptor */ mysql_declare_plugin(audit_syslog) {   MYSQL_AUDIT_PLUGIN,           /* plugin type                    */   &audit_syslog_descriptor,     /* descriptor handle               */   "audit_syslog",               /* plugin name                     */   "Author Name",                /* author                          */   "Simple Syslog Audit",        /* description                     */   PLUGIN_LICENSE_GPL,           /* licence                         */   audit_syslog_init,            /* init function     */   audit_syslog_deinit,          /* deinit function */   0x0001,                       /* plugin version                  */   NULL,                         /* status variables        */   NULL,                         /* system variables                */   NULL,                         /* no reserves                     */   0,                            /* no flags                        */ } mysql_declare_plugin_end; The general plugin descriptor above is standard for all plugin types in MySQL. The plugin type is defined along with the init/deinit functions and interface methods into the system for sharing information, and various other metadata information. The descriptors have an internally recognised version number so that plugins can be matched against the api on the running server. The other details are usually related to the type-specific methods and structures to implement the plugin. Each plugin has a type-specific descriptor as well which details how the plugin is implemented for the specific purpose of that plugin type. /*   Plugin type-specific descriptor */ static struct st_mysql_audit audit_syslog_descriptor= {   MYSQL_AUDIT_INTERFACE_VERSION,                        /* interface version    */   NULL,                                                 /* release_thd function */   audit_syslog_notify,                                  /* notify function      */   { (unsigned long) MYSQL_AUDIT_GENERAL_CLASSMASK |                     MYSQL_AUDIT_CONNECTION_CLASSMASK }  /* class mask           */ }; In this particular case, the release_thd function has not been defined as it is not required. The important method for auditing is the notify function which is activated when an event occurs on the system. The notify function is designed to activate on an event and the implementation will determine how it is handled. For the audit_syslog plugin, the use of the syslog feature sends all events to the syslog for recording. The class mask allows us to determine what type of events are being seen by the notify function. There are currently two major types of event: 1. General Events: This includes general logging, errors, status and result type events. This is the main one for tracking the queries and operations on the database. 2. Connection Events: This group is based around user logins. It monitors connections and disconnections, but also if somebody changes user while connected. With most audit plugins, the principle behind the plugin is to track changes to the system over time and counters can be an important part of this process. The next step is to define and initialise the counters that are used to track the events in the service. There are 3 counters defined in total for our plugin - the # of general events, the # of connection events and the total number of events.  static volatile int total_number_of_calls; /* Count MYSQL_AUDIT_GENERAL_CLASS event instances */ static volatile int number_of_calls_general; /* Count MYSQL_AUDIT_CONNECTION_CLASS event instances */ static volatile int number_of_calls_connection; The init and deinit functions for the plugin are there to be called when the plugin is activated and when it is terminated. These offer the best option to initialise the counters for our plugin: /*  Initialize the plugin at server start or plugin installation. */ static int audit_syslog_init(void *arg __attribute__((unused))) {     openlog("mysql_audit:",LOG_PID|LOG_PERROR|LOG_CONS,LOG_USER);     total_number_of_calls= 0;     number_of_calls_general= 0;     number_of_calls_connection= 0;     return(0); } The init function does a call to openlog to initialise the syslog functionality. The parameters are the service to log under ("mysql_audit" in this case), the syslog flags and the facility for the logging. Then each of the counters are initialised to zero and a success is returned. If the init function is not defined, it will return success by default. /*  Terminate the plugin at server shutdown or plugin deinstallation. */ static int audit_syslog_deinit(void *arg __attribute__((unused))) {     closelog();     return(0); } The deinit function will simply close our syslog connection and return success. Note that the syslog functionality is part of the glibc libraries and does not require any external factors.  The function names are what we define in the general plugin structure, so these have to match otherwise there will be errors. The next step is to implement the event notifier function that was defined in the type specific descriptor (audit_syslog_descriptor) which is audit_syslog_notify. /* Event notifier function */ static void audit_syslog_notify(MYSQL_THD thd __attribute__((unused)), unsigned int event_class, const void *event) { total_number_of_calls++; if (event_class == MYSQL_AUDIT_GENERAL_CLASS) { const struct mysql_event_general *event_general= (const struct mysql_event_general *) event; number_of_calls_general++; syslog(audit_loglevel,"%lu: User: %s Command: %s Query: %s\n", event_general->general_thread_id, event_general->general_user, event_general->general_command, event_general->general_query ); } else if (event_class == MYSQL_AUDIT_CONNECTION_CLASS) { const struct mysql_event_connection *event_connection= (const struct mysql_event_connection *) event; number_of_calls_connection++; syslog(audit_loglevel,"%lu: User: %s@%s[%s] Event: %d Status: %d\n", event_connection->thread_id, event_connection->user, event_connection->host, event_connection->ip, event_connection->event_subclass, event_connection->status ); } }   In the case of an event, the notifier function is called. The first step is to increment the total number of events that have occurred in our database.The event argument is then cast into the appropriate event structure depending on the class type, of general event or connection event. The event type counters are incremented and details are sent via the syslog() function out to the system log. There are going to be different line formats and information returned since the general events have different data compared to the connection events, even though some of the details overlap, for example, user, thread id, host etc. On compiling the code now, there should be no errors and the resulting audit_syslog.so can be loaded into the server and ready to use. Log into the server and type: mysql> INSTALL PLUGIN audit_syslog SONAME 'audit_syslog.so'; This will install the plugin and will start updating the syslog immediately. Note that the audit plugin attaches to the immediate thread and cannot be uninstalled while that thread is active. This means that you cannot run the UNISTALL command until you log into a different connection (thread) on the server. Once the plugin is loaded, the system log will show output such as the following: Oct  8 15:33:21 machine mysql_audit:[8337]: 87: User: root[root] @ localhost []  Command: (null)  Query: INSTALL PLUGIN audit_syslog SONAME 'audit_syslog.so' Oct  8 15:33:21 machine mysql_audit:[8337]: 87: User: root[root] @ localhost []  Command: Query  Query: INSTALL PLUGIN audit_syslog SONAME 'audit_syslog.so' Oct  8 15:33:40 machine mysql_audit:[8337]: 87: User: root[root] @ localhost []  Command: (null)  Query: show tables Oct  8 15:33:40 machine mysql_audit:[8337]: 87: User: root[root] @ localhost []  Command: Query  Query: show tables Oct  8 15:33:43 machine mysql_audit:[8337]: 87: User: root[root] @ localhost []  Command: (null)  Query: select * from t1 Oct  8 15:33:43 machine mysql_audit:[8337]: 87: User: root[root] @ localhost []  Command: Query  Query: select * from t1 It appears that two of each event is being shown, but in actuality, these are two separate event types - the result event and the status event. This could be refined further by changing the audit_syslog_notify function to handle the different event sub-types in a different manner.  So far, it seems that the logging is working with events showing up in the syslog output. The issue now is that the counters created earlier to track the number of events by type are not accessible when the plugin is being run. Instead there needs to be a way to expose the plugin specific information to the service and vice versa. This could be done via the information_schema plugin api, but for something as simple as counters, the obvious choice is the system status variables. This is done using the standard structure and the declaration: /*  Plugin status variables for SHOW STATUS */ static struct st_mysql_show_var audit_syslog_status[]= {   { "Audit_syslog_total_calls",     (char *) &total_number_of_calls,     SHOW_INT },   { "Audit_syslog_general_events",     (char *) &number_of_calls_general,     SHOW_INT },   { "Audit_syslog_connection_events",     (char *) &number_of_calls_connection,     SHOW_INT },   { 0, 0, SHOW_INT } };   The structure is simply the name that will be displaying in the mysql service, the address of the associated variables, and the data type being used for the counter. It is finished with a blank structure to show that there are no more variables. Remember that status variables may have the same name for variables from other plugin, so it is considered appropriate to add the plugin name at the start of the status variable name to avoid confusion. Looking at the status variables in the mysql client shows something like the following: mysql> show global status like "audit%"; +--------------------------------+-------+ | Variable_name                  | Value | +--------------------------------+-------+ | Audit_syslog_connection_events | 1     | | Audit_syslog_general_events    | 2     | | Audit_syslog_total_calls       | 3     | +--------------------------------+-------+ 3 rows in set (0.00 sec) The final connectivity piece for the plugin is to allow the interactive change of the logging level between the plugin and the system. This requires the ability to send changes via the mysql service through to the plugin. This is done using the system variables interface and defining a single variable to keep track of the active logging level for the facility. /* Plugin system variables for SHOW VARIABLES */ static MYSQL_SYSVAR_STR(loglevel, audit_loglevel,                         PLUGIN_VAR_RQCMDARG,                         "User can specify the log level for auditing",                         audit_loglevel_check, audit_loglevel_update, "LOG_NOTICE"); static struct st_mysql_sys_var* audit_syslog_sysvars[] = {     MYSQL_SYSVAR(loglevel),     NULL }; So now the system variable 'loglevel' is defined for the plugin and associated to the global variable 'audit_loglevel'. The check or validation function is defined to make sure that no garbage values are attempted in the update of the variable. The update function is used to save the new value to the variable. Note that the audit_syslog_sysvars structure is defined in the general plugin descriptor to associate the link between the plugin and the system and how much they interact. Next comes the implementation of the validation function and the update function for the system variable. It is worth noting that if you have a simple numeric such as integers for the variable types, the validate function is often not required as MySQL will handle the automatic check and validation of simple types. /* longest valid value */ #define MAX_LOGLEVEL_SIZE 100 /* hold the valid values */ static const char *possible_modes[]= { "LOG_ERROR", "LOG_WARNING", "LOG_NOTICE", NULL };  static int audit_loglevel_check(     THD*                        thd,    /*!< in: thread handle */     struct st_mysql_sys_var*    var,    /*!< in: pointer to system                                         variable */     void*                       save,   /*!< out: immediate result                                         for update function */     struct st_mysql_value*      value)  /*!< in: incoming string */ {     char buff[MAX_LOGLEVEL_SIZE];     const char *str;     const char **found;     int length;     length= sizeof(buff);     if (!(str= value->val_str(value, buff, &length)))         return 1;     /*         We need to return a pointer to a locally allocated value in "save".         Here we pick to search for the supplied value in an global array of         constant strings and return a pointer to one of them.         The other possiblity is to use the thd_alloc() function to allocate         a thread local buffer instead of the global constants.     */     for (found= possible_modes; *found; found++)     {         if (!strcmp(*found, str))         {             *(const char**)save= *found;             return 0;         }     }     return 1; } The validation function is simply to take the value being passed in via the SET GLOBAL VARIABLE command and check if it is one of the pre-defined values allowed  in our possible_values array. If it is found to be valid, then the value is assigned to the save variable ready for passing through to the update function. static void audit_loglevel_update(     THD*                        thd,        /*!< in: thread handle */     struct st_mysql_sys_var*    var,        /*!< in: system variable                                             being altered */     void*                       var_ptr,    /*!< out: pointer to                                             dynamic variable */     const void*                 save)       /*!< in: pointer to                                             temporary storage */ {     /* assign the new value so that the server can read it */     *(char **) var_ptr= *(char **) save;     /* assign the new value to the internal variable */     audit_loglevel= *(char **) save; } Since all the validation has been done already, the update function is quite simple for this plugin. The first part is to update the system variable pointer so that the server can read the value. The second part is to update our own global plugin variable for tracking the value. Notice that the save variable is passed in as a void type to allow handling of various data types, so it must be cast to the appropriate data type when assigning it to the variables. Looking at how the latest changes affect the usage of the plugin and the interaction within the server shows: mysql> show global variables like "audit%"; +-----------------------+------------+ | Variable_name         | Value      | +-----------------------+------------+ | audit_syslog_loglevel | LOG_NOTICE | +-----------------------+------------+ 1 row in set (0.00 sec) mysql> set global audit_syslog_loglevel="LOG_ERROR"; Query OK, 0 rows affected (0.00 sec) mysql> show global status like "audit%"; +--------------------------------+-------+ | Variable_name                  | Value | +--------------------------------+-------+ | Audit_syslog_connection_events | 1     | | Audit_syslog_general_events    | 11    | | Audit_syslog_total_calls       | 12    | +--------------------------------+-------+ 3 rows in set (0.00 sec) mysql> show global variables like "audit%"; +-----------------------+-----------+ | Variable_name         | Value     | +-----------------------+-----------+ | audit_syslog_loglevel | LOG_ERROR | +-----------------------+-----------+ 1 row in set (0.00 sec)   So now we have a plugin that will audit the events on the system and log the details to the system log. It allows for interaction to see the number of different events within the server details and provides a mechanism to change the logging level interactively via the standard system methods of the SET command. A more complex auditing plugin may have more detailed code, but each of the above areas is what will be involved and simply expanded on to add more functionality. With the above skeleton code, it is now possible to create your own audit plugins to implement your own auditing requirements. If, however, you are not of the coding persuasion, then you could always consider the option of the MySQL Enterprise Audit plugin that is available to purchase.

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  • value types in the vm

    - by john.rose
    value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases.  Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both.  We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types.  These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im,         /*Complex y:*/ double y_re, double y_im) {     /*Complex z = x.minus(y):*/     double z_re = x_re - y_re, z_im = x_im - y_im;     /*return z.abs():*/     return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable {     // immutable component structure:     public final double re, im;     private Complex(double re, double im) {         this.re = re; this.im = im;     }     // interoperability methods:     public String toString() { return "Complex("+re+","+im+")"; }     public List<Double> asList() { return Arrays.asList(re, im); }     public boolean equals(Complex c) {         return re == c.re && im == c.im;     }     public boolean equals(@ValueSafe Object x) {         return x instanceof Complex && equals((Complex) x);     }     public int hashCode() {         return 31*Double.valueOf(re).hashCode()                 + Double.valueOf(im).hashCode();     }     // factory methods:     public static Complex valueOf(double re, double im) {         return new Complex(re, im);     }     public Complex changeRe(double re2) { return valueOf(re2, im); }     public Complex changeIm(double im2) { return valueOf(re, im2); }     public static Complex cast(@ValueSafe Object x) {         return x == null ? ZERO : (Complex) x;     }     // utility methods and constants:     public Complex plus(Complex c)  { return new Complex(re+c.re, im+c.im); }     public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); }     public double abs() { return Math.sqrt(re*re + im*im); }     public static final Complex PI = valueOf(Math.PI, 0.0);     public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts.  The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final.  (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations.  A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations.  No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type.  If a value-safe class is marked final, it is in fact a value type.  All other value-safe classes must be abstract.  The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex.  Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable {     // All methods listed here must get redefined.     // Definitions must be value-safe, which means     // they may depend on component values only.     List<? extends Object> asList();     int hashCode();     boolean equals(@ValueSafe Object c);     String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system.  It could appear as an element type or parameter bound, for facilities which are designed to work on value types only.  More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods.  (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.)  Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation.  In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation.  Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0);  //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe")   Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object();  // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi);  // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi);  // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi);  // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero);  // error: reference comparison on value type boolean z2 = (pi == null);  // error: reference comparison on value type boolean z3 = (pi == obj2);  // error: reference comparison on value type synchronized (pi) { }  // error: synch of value, unpredictable result synchronized (obj2) { }  // unpredictable result Complex qq = pi; qq = null;  // possible NPE; warning: “null-unsafe" qq = (Complex) obj;  // warning: “null-unsafe" qq = Complex.cast(obj);  // OK @SuppressWarnings("null-unsafe")   Complex empty = null;  // possible NPE qq = empty;  // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations.  Fields and variables of value types can be split into their unboxed components.  Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules?  Why not detect programs automagically and perform unboxing transparently?  The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced.  Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal.  In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur.  This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer.  Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules.  There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme.  Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions.  One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type.  That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances.  Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe.  Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around.  Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed.  This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods.  This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors.  The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type.  Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands.  When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not.  If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible.  Proxies must be managed carefully, and this can be expensive.  On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces.  (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.)  Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems.  They require the deepest transformations, relative to today’s JVM.  There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics.  It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form.  Such value-safe arrays would not be convertible to Object[] arrays.  Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex.  I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code.  On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly.  Likewise, there are rules for providing default access modifiers for interface members.  Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types.  Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType {  // implicitly final     public double re, im;  // implicitly public final     //implicit methods are defined elementwise from te fields:     //  toString, asList, equals(2), hashCode, valueOf, cast     //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner.  The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer.  A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point.  The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage?  Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number.  Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”).  What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple {      double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly.  The supertype is an abstract class which has suitable shared declarations.  The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it.  The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types.  (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language.  (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.)  At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists.  Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection.  That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types.  Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API.  The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components  that appear as parameters, return types, and array elements.  This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations.  A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile.  Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type.  It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack.  If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction?  Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot.  But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes.  I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value.  Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType {     protected final long header;     protected private final BigInteger digits;     public DecimalValue valueOf(int value, int scale) {         assert(scale >= 0);         return new DecimalValue(((long)value << 32) + scale, null);     }     public DecimalValue valueOf(long value, int scale) {         if (value == (int) value)             return valueOf((int)value, scale);         return new DecimalValue(-scale, new BigInteger(value));     } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case.  It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues.  (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.)  Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits.  For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types.  This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant.  An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes.  More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable,         Unsynchronizable, Interchangeable { … public class Complex implements ValueType {     // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe     … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types.  This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable.  It is likely that code which violates value-safety for wrapper types exists but is uncommon.  It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code.  The design presented above obscures that distinction.  As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations.  Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed.  For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi;  // convert to boxed myList.add(boxPi); complex z = myList.get(0);  // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM.  Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type.  Something like this which can also accommodate value type components seems worthwhile.  On the other hand, does it make sense for value types to contain short arrays?  And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure.  These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types.  In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids.  No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now.  Back to work!

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  • The Message Queuing service failed to join the computer's domain 'DOMAIN' Error 0xc00e0025

    - by SimonGoldstone
    Struggling to get MSMQ installed in Domain Integration mode on Windows 2012 (Azure). So far, I've provisioned a brand new Windows Server 2012 (R2) machine on the Azure platform and installed the Active Directory role and promoted the machine to a domain controller. Once the AD was in place, I then added the MSMQ feature, along with the Directory Integration add on. However, it will not install in AD integration mode. It will only work in Workgroup mode. I can verify this by running the following powershell command: New-MSMQQueue -name Queue1 -queuetype Public When I run this command, I get the following error: New-MsmqQueue : A workgroup installation computer does not support the operation. The event viewer reveals to errors in the Application log: 1. The Message Queuing service failed to join the computer's domain 'DOMAIN'. Error 0xc00e0025: 2. Message Queuing was unable to create the msmq (MSMQ Configuration) object in Active Directory Domain Services. Error c00e0025h: I'm struggling here. Any advice?

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  • Does Hyper-V support SCSI Pass-through discs in a Server 2003 R2 VM?

    - by Peter Bernier
    I'm running into some difficulties getting pass-through disks to be accessible to a Hyper-v server 2003 r2 virtual machine. Host OS : Server 2008 R2 full w/Hyper-V role Guest OS : Server 2003 R2 (Windows Home Server) The guest's OS disk is a pass-through disk on the IDE controller (not the best solution, but I can live with it). My storage disks will be pass-through disks on the SCSI controller. I'm able to see all of the disks that I'll be using for the VM on the host without issue. The problem that I'm having is that I can't seem to get the guest OS to be able to 'see' the storage drives (as pass-through disks on the SCSI controller). Here's what I'm doing : On the host, the storage drive is set to 'Offline' just like the OS disk (this is required for pass-through to work). In the VM, the storage drive is on the SCSI controller. Hyper-V Integration Tools are installed in guest. That's as far as I'm able to get. I don't see the drive in Computer Management, or in Windows Explorer (I've tried with an unformatted disk, as well as after formatting a partition). I am able to see a removable device that lists the disk's model number in the Guest, but I can't seem to access the storage. (I get an entry in Device Manager that needs drivers, but nothing on the Integration Tools disc works..) Trouble-shooting steps I've tried : If put the pass-through drive on the IDE controller, I can see it in the Guest. If put the storage drive 'Online' in the host and create a VHD on it on the SCSI controller, I can see it in the Guest. I suppose I could create a fixed-size VHD that consumes the entire disk, but I'd rather not have that overhead. I've also extracted the contents of the Integration Tools drivers (x86 and amd64) and tried pointing the disk controller to each of those, with no luck. Can anyone offer suggestions as to how I can get this to work properly?

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  • Guidelines for using Merge task in SSIS

    - by thursdaysgeek
    I have a table with three fields, one an identity field, and I need to add some new records from a source that has the other two fields. I'm using SSIS, and I think I should use the merge tool, because one of the sources is not in the local database. But, I'm confused by the merge tool and the proper process. I have my one source (an Oracle table), and I get two fields, well_id and well_name, with a sort after, sorting by well_id. I have the destination table (sql server), and I'm also using that as a source. It has three fields: well_key (identity field), well_id, and well_name, and I then have a sort task, sorting on well_id. Both of those are input to my merge task. I was going to output to a temporary table, and then somehow get the new records back into the sql server table. Oracle Well SQL Well | | V V Sort Source Sort Well | | -------> Merge* <----------- | V Temp well table I suspect this isn't the best way to use this tool, however. What are the proper steps for a merge like this? One of my reasons for questioning this method is that my merge has an error, telling me that the "Merge Input 2" must be sorted, but its source is a sort task, so it IS sorted. Example data SQL Well (before merge) well_key well_id well_name 1 123 well k 2 292 well c 3 344 well t 5 439 well d Oracle Well well_id well_name 123 well k 292 well c 311 well y 344 well t 439 well d 532 well j SQL Well (after merge) well_key well_id well_name 1 123 well k 2 292 well c 3 344 well t 5 439 well d 6 311 well y 7 532 well j Would it be better to load my Oracle Well to a temporary local file, and then just use a sql insert statment on it?

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  • Blocking on DBCP connection pool (open and close connnection). Is database connection pooling in OpenEJB pluggable?

    - by topchef
    We use OpenEJB on Tomcat (used to run on JBoss, Weblogic, etc.). While running load tests we experience significant performance problems with handling JMS messages (queues). Problem was localized to blocking on database connection pool getting or releasing connection to the pool. Blocking prevented concurrent MDB instances (threads) from running hence performance suffered 10-fold and worse. The same code used to run on application servers (with their respective connection pool implementations) with no blocking at all. Example of thread blocked: Name: JMS Resource Adapter-worker-23 State: BLOCKED on org.apache.commons.pool.impl.GenericObjectPool@1ea6b4a owned by: JMS Resource Adapter-worker-19 Total blocked: 18,426 Total waited: 0 Stack trace: org.apache.commons.pool.impl.GenericObjectPool.returnObject(GenericObjectPool.java:916) org.apache.commons.dbcp.PoolableConnection.close(PoolableConnection.java:91) - locked org.apache.commons.dbcp.PoolableConnection@1bcba8 org.apache.commons.dbcp.managed.ManagedConnection.close(ManagedConnection.java:147) com.xxxxx.persistence.DbHelper.closeConnection(DbHelper.java:290) .... Couple of questions. I am almost certain that some transactional attributes and properties contribute to this blocking, but MDBs are defined as non-transactional (we use both annotations and ejb-jar.xml). Some EJBs do use container-managed transactions though (and we can observe blocking there as well). Are there any DBCP configurations that may fix blocking? Is DBCP connection pool implementation replaceable in OpenEJB? How easy (difficult) to replace it with another library? Just in case this is how we define data source in OpenEJB (openejb.xml): <Resource id="MyDataSource" type="DataSource"> JdbcDriver oracle.jdbc.driver.OracleDriver JdbcUrl ${oracle.jdbc} UserName ${oracle.user} Password ${oracle.password} JtaManaged true InitialSize 5 MaxActive 30 ValidationQuery SELECT 1 FROM DUAL TestOnBorrow true </Resource>

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  • How to test a struts 2.1.x developer?

    - by Jason Pyeron
    We employ test to filter out those who can't. The tests are designed to be very low effort for those who can and too much effort for those who can't. Here is an example for java web application developer on an Oracle project: We only work with contractors who can use the tools we use, to determine if you can use the tools we have devised some very simple tests. Instructions If you are prepared and knowledgeable this will take you about 2-5 minutes. Suggested knowledge and tools: * subversion 1.6 see http://subversion.tigris.org/ or http://cygwin.com/setup.exe * java 1.6 see http://java.sun.com/javase/downloads/index.jsp * oracle >=10g see http://www.oracle.com/technology/software/products/jdev/index.html * j2ee server see http://tomcat.apache.org/download-55.cgi or http://www.jboss.org/jbossas/downloads/ Steps 1. check out svn://statics32.pdinc.us/home/subversion/guest 2. deploy the war file found at trunk/test.war 3. browse to the web application you installed from the war file and answer the one SQL question: How many rows are in the table 'testdata' where column 'value' ends with either an 'A' or an 'a'? The login credentials are in trunk/doc/oracle.txt 4. make a RESULTS HASH by submitting your answer to the form. 5. create a file in tmp/YourUserName.txt and put the RESULTS HASH in it, not the answer. 6. check in your file (don't forget to add the file first). 7. message me with the revision number of your check in. As such I am looking for ideas on how to test for someone to be a struts 2.1 w/ annotations.

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  • Duplicate C# web service proxy classes generated for Java types

    - by Sergey
    My question is about integration between a Java web service and a C# .NET client. Service: CXF 2.2.3 with Aegis databinding Client: C#, .NET 3.5 SP1 For some reason Visual Studio generates two C# proxy enums for each Java enum. The generated C# classes do not compile. For example, this Java enum: public enum SqlDialect { GENERIC, SYBASE, SQL_SERVER, ORACLE; } Produces this WSDL: <xsd:simpleType name="SqlDialect"> <xsd:restriction base="xsd:string"> <xsd:enumeration value="GENERIC" /> <xsd:enumeration value="SYBASE" /> <xsd:enumeration value="SQL_SERVER" /> <xsd:enumeration value="ORACLE" /> </xsd:restriction> </xsd:simpleType> For this WSDL Visual Studio generates two partial C# classes (generated comments removed): [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "3.0.0.0")] [System.Runtime.Serialization.DataContractAttribute(Name="SqlDialect", Namespace="http://somenamespace")] public enum SqlDialect : int { [System.Runtime.Serialization.EnumMemberAttribute()] GENERIC = 0, [System.Runtime.Serialization.EnumMemberAttribute()] SYBASE = 1, [System.Runtime.Serialization.EnumMemberAttribute()] SQL_SERVER = 2, [System.Runtime.Serialization.EnumMemberAttribute()] ORACLE = 3, } [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Xml", "2.0.50727.3082")] [System.SerializableAttribute()] [System.Xml.Serialization.XmlTypeAttribute(Namespace="http://somenamespace")] public enum SqlDialect { GENERIC, SYBASE, SQL_SERVER, ORACLE, } The resulting C# code does not compile: The namespace 'somenamespace' already contains a definition for 'SqlDialect' I will appreciate any ideas...

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  • How to fix “Add Host to Workflow Farm problem” when installing Windows Azure Workflow in SharePoint2013 Preview

    - by ybbest
    Problem: When I try to configure the windows Azure workflow in SharePoint2013 preview, I got the following error see screenshot below. Detailed log can be found here. Solution: I asked the question in SharePoint StackExchange , Rajat’s help me to fix the problem .The solution for this is quite simple, instead of using the short form for your RunAs account, you should use the fully qualified name. So change administrator@YBBEST to [email protected] make the problem go away as shown below. References: How to: Set up and configure SharePoint 2013 workflows

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  • EFMVC Migrated to .NET 4.5, Visual Studio 2012, ASP.NET MVC 4 and EF 5 Code First

    - by shiju
    I have just migrated my EFMVC app from .NET 4.0 and ASP.NET MVC 4 RC to .NET 4.5, ASP.NET MVC 4 RTM and Entity Framework 5 Code First. In this release, the EFMVC solution is built with Visual Studio 2012 RTM. The migration process was very smooth and did not made any major changes other than adding simple unit tests with NUnit and Moq. I will add more unit tests on later and will also modify the existing solution. Source Code You can download the source code from http://efmvc.codeplex.com/

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  • Sorting a ListView in WPF – Part II

    - by marianor
    Some time ago I wrote a post about how to sort a ListView by clicking on the header of the column. The problem with that solution was that you needed to implement it each time and you have to define an explicit header for each column. As a more general solution I use attached properties to extend the ListView and GridViewColumn . The first attached property is tied to the ListView itself, and it indicates that the control supports sorting. This property attach or detach to the Click event of the...(read more)

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  • CodePlex Daily Summary for Sunday, April 04, 2010

    CodePlex Daily Summary for Sunday, April 04, 2010New ProjectsAcervo 2 - Gerenciador de coleções: Acervo 2 is a web application developed in ASP.NET 3.5 with Entity Framework, Coolite UI web controls and MySQL database that helps to catalog and ...AssemblyInfo Editor: AssemblyInfo Editor is a small Visual Studio 2010 extension I developed for my personal use mainly for automatically incrementing AssemblyVersion a...CommLine: It's a Command Line Interpreter. At the moment, it's a beta version, so I wait for developers that wanna help meFlowgraph Viewer: The flowgraph viewer enables users to view, build and share flowgraphs for the Crysis-franchise. It's built on Silverlight4, using MEF and Mvvmlight.Hash Calculator: WPF Windows 7 program to compute SHA1 & MD5 hash functions.MediaRSS library for .NET: This is a small set of libraries that allow you to create, read, and write MediaRSS files. By leveraging the syndication model object in .NET this...MEF Visualizer Tool: Helps to see what is going on inside the CompositionContainerone framework for developing asp.net project more elegent、flexible、and testable: if you are familiar with jsf、cdi、scoped javabean and work under asp.net, you may want to support aop and max flexibility and testability , all of ...Picasa Manager: A Silverlight Out Of Browser Application that Helps you manage your PicasaWeb albums in the easyest way possible.SharePhone: Windows Phone 7 library for connecting to SharePoint 2007/2010. Lets you work with SPWeb, SPList, reading/writing strong typed list items, user ...Silverlight Resource Extension: Silverlight Resource Extension. Extension silverlight project for use ResX resources and localize satellite dll.Silverlight Streamgraph: Streamgraph component for SilverlightTFTP Server: Managed TFTP server implementation, written in C#. Supports: - IPv4 and IPv6 - correct retry behavior. - TFTP options: block size, transfer size, a...Virtual UserGroup Video Helpers: This is a project that holds all the tools used by the C4MVC Virtual Usergroup. Tools written in C# and Powershell to automate, Live Meeting, Expr...xBlog: xBlog is a project to build a simple and extensible Blog Engine based on xml and linqXmlCodeEditor: XmlCodeEditor is a Silverlight 4 control based on RichTextControl that creates coloring and intellisense similar to the one in Visual Studio for ed...Zinc Launcher: Zinc Launcher is a simple Windows Media Center plugin that launches Zinc and attempts to manage the windows as seamlessly as possible. In addition ...New ReleasesAcervo 2 - Gerenciador de coleções: Acervo 2 - v1.0: Arquivos para implantação do sistema Acervo2 Aplicação web Web service Smart ClientAssemblyInfo Editor: Beta 1: Initial release of Assembly Info Editor. At this point, it is feature-complete and is relatively stable. There are undoubtedly some bugs to work o...Box2D.XNA: Box2D.XNA r70 Source Code and Solution: This version is synced to changeset 44697. This represents our official port of the C Box2D up to r70 on the Google Code project. With this versi...Boxee Launcher: Boxee Launcher Release 1.0.1.2: Will now stop Media Center playback before launching BoxeeBoxee Launcher: Boxee Launcher Release 1.0.1.3: Added a background window that attempts to display over the desktop and taskbar, and below Boxee and Media Center so that the desktop and taskbar a...CommLine: Beta Version 0.1: First Beta Of the AppCommLine: Source v0.1 Beta: Source Code C of 0.1 beta versionEncrypted Notes: Encrypted Notes 1.6.2: This is the latest version of Encrypted Notes (1.6.2), with general changes and improved randomness for the key generator. It has an installer that...Hash Calculator: HashCalculator: HashCalculator 1.0Hash Calculator: HashCalculator Source code: HashCalculator 1.0Hulu Launcher: Hulu Launcher 1.0.1.3: Added a background window that attempts to display over the desktop and taskbar, and below Hulu and Media Center so that the desktop and taskbar ar...Hulu Launcher: Hulu Launcher Release 1.0.1.2: Hulu Launcher will now stop playback in Media Center before launching Hulu Desktop.Innovative Games: 4.3 - Sprite Effects: Source code download for chapter 4.3 - "Sprite Effects"MediaRSS library for .NET: 0.1: Alpha release. Majority of MediaRSS spec is supported. A small set of unit test / sample code are included. A lightly tested CustomFormatter object...MEF Visualizer Tool: MEF Visualizer Tool 0.1: Help to see what going on in side CompositionContainer Container = new CompositionContainer( new AggregateCatalog( ...Ncqrs Framework - A CQRS framework for .NET: Ncqrs with sample application: This is the first release of the Ncqrs Framework. It contains the Ncqrs source code and a runnable sample application. All the code in this release...Rubik Cube's 3D Silverlight 3.0 Animated Solution: Rubik Cube 3D with Animated Solution: This project is a realization of Silverlight 3.0 Rubik Cube 3D with Animated Solution. The Solution is available for 3x3x3 cube, other features are...Scrabler: scrabler release 0.6.2.5: fixed a bug that werent executed some scriptsSharePhone: SharePhone: Initial release with basic functionality: Open SharePoint webs and subwebs Retrieve lists on SPWeb objects Read metadata/properties on lists ...SharePhone: SharePhone v.1.0.1: Fixed a bug that prevented saving list items to SharePointSharePoint Labs: SPLab4001A-FRA-Level100: SPLab4001A-FRA-Level100 This SharePoint Lab will teach you the first best practice you should apply when writing code with the SharePoint API. Lab ...Silverlight Resource Extension: ResourceExtension (alpha): Alpha version is not stable. Only for review.Silverlight Streamgraph: Port from processing.org: A port from the processing.org streamgraph. Code-heavy with very little XAML involved at this point.Theocratic Ministry School System: TMSS - Ver 1.1.1: What’s New! Added Menu Options 2010 Schedule Access 2007 Runtime There are still many uncompleted items so this is still a conceptual release....Theocratic Ministry School System: TMSS - Ver 1.1.2: Fixed the Schedule Import. Need needs to be tested. Click import button and make sure you can get the 2010 Schedule from the internet.thinktecture Starter STS (Community Edition): StarterSTS v1.0 RTW: Version 1.0 RTWTribe.Cache: Tribe.Cache Alpha - 0.2.0.0: Tribe.Cache Alpha - 0.2.0.0 - Now has sliding and absolute expiration on cache entries. Functional Alpha Release - But do not use in productionTwitterVB - A .NET Twitter Library: TwitterVB-2.3.1: This is mostly a minor release that adds br.st URL shortening to the menu (API key from http://br.st required)Virtu: Virtu 0.8.1: Source Requirements.NET Framework 3.5 with Service Pack 1 Visual Studio 2008 with Service Pack 1, or Visual C# 2008 Express Edition with Service Pa...Visual Studio DSite: Advanced C++ Calculator: An advanced visual c 2008 calculator that can do all your basic operations, plus some advanced mathematical functions. Source Code Only.xnaWebcam: xnaWebcam 0.3: xnaWebcam 0.3 Version 0.3: -ResolutionSet: 400x300 (Default), 800x600, 1024x720 -Settings Window got Icon -Settings Window Changes -DevConsole.cs ...Most Popular ProjectsRawrWBFS ManagerMicrosoft SQL Server Product Samples: DatabaseASP.NET Ajax LibrarySilverlight ToolkitAJAX Control ToolkitWindows Presentation Foundation (WPF)ASP.NETMicrosoft SQL Server Community & SamplesDotNetNuke® Community EditionMost Active ProjectsGraffiti CMSnopCommerce. Open Source online shop e-commerce solution.RawrFacebook Developer ToolkitjQuery Library for SharePoint Web ServicesLINQ to TwitterBlogEngine.NETN2 CMSBase Class LibrariesFarseer Physics Engine

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  • SQL SERVER – Extending SQL Azure with Azure worker role – Guest Post by Paras Doshi

    - by pinaldave
    This is guest post by Paras Doshi. Paras Doshi is a research Intern at SolidQ.com and a Microsoft student partner. He is currently working in the domain of SQL Azure. SQL Azure is nothing but a SQL server in the cloud. SQL Azure provides benefits such as on demand rapid provisioning, cost-effective scalability, high availability and reduced management overhead. To see an introduction on SQL Azure, check out the post by Pinal here In this article, we are going to discuss how to extend SQL Azure with the Azure worker role. In other words, we will attempt to write a custom code and host it in the Azure worker role; the aim is to add some features that are not available with SQL Azure currently or features that need to be customized for flexibility. This way we extend the SQL Azure capability by building some solutions that run on Azure as worker roles. To understand Azure worker role, think of it as a windows service in cloud. Azure worker role can perform background processes, and to handle processes such as synchronization and backup, it becomes our ideal tool. First, we will focus on writing a worker role code that synchronizes SQL Azure databases. Before we do so, let’s see some scenarios in which synchronization between SQL Azure databases is beneficial: scaling out access over multiple databases enables us to handle workload efficiently As of now, SQL Azure database can be hosted in one of any six datacenters. By synchronizing databases located in different data centers, one can extend the data by enabling access to geographically distributed data Let us see some scenarios in which SQL server to SQL Azure database synchronization is beneficial To backup SQL Azure database on local infrastructure Rather than investing in local infrastructure for increased workloads, such workloads could be handled by cloud Ability to extend data to different datacenters located across the world to enable efficient data access from remote locations Now, let us develop cloud-based app that synchronizes SQL Azure databases. For an Introduction to developing cloud based apps, click here Now, in this article, I aim to provide a bird’s eye view of how a code that synchronizes SQL Azure databases look like and then list resources that can help you develop the solution from scratch. Now, if you newly add a worker role to the cloud-based project, this is how the code will look like. (Note: I have added comments to the skeleton code to point out the modifications that will be required in the code to carry out the SQL Azure synchronization. Note the placement of Setup() and Sync() function.) Click here (http://parasdoshi1989.files.wordpress.com/2011/06/code-snippet-1-for-extending-sql-azure-with-azure-worker-role1.pdf ) Enabling SQL Azure databases synchronization through sync framework is a two-step process. In the first step, the database is provisioned and sync framework creates tracking tables, stored procedures, triggers, and tables to store metadata to enable synchronization. This is one time step. The code for the same is put in the setup() function which is called once when the worker role starts. Now, the second step is continuous (or on demand) synchronization of SQL Azure databases by propagating changes between databases. This is done on a continuous basis by calling the sync() function in the while loop. The code logic to synchronize changes between SQL Azure databases should be put in the sync() function. Discussing the coding part step by step is out of the scope of this article. Therefore, let me suggest you a resource, which is given here. Also, note that before you start developing the code, you will need to install SYNC framework 2.1 SDK (download here). Further, you will reference some libraries before you start coding. Details regarding the same are available in the article that I just pointed to. You will be charged for data transfers if the databases are not in the same datacenter. For pricing information, go here Currently, a tool named DATA SYNC, which is built on top of sync framework, is available in CTP that allows SQL Azure <-> SQL server and SQL Azure <-> SQL Azure synchronization (without writing single line of code); however, in some cases, the custom code shown in this blogpost provides flexibility that is not available with Data SYNC. For instance, filtering is not supported in the SQL Azure DATA SYNC CTP2; if you wish to have such a functionality now, then you have the option of developing a custom code using SYNC Framework. Now, this code can be easily extended to synchronize at some schedule. Let us say we want the databases to get synchronized every day at 10:00 pm. This is what the code will look like now: (http://parasdoshi1989.files.wordpress.com/2011/06/code-snippet-2-for-extending-sql-azure-with-azure-worker-role.pdf) Don’t you think that by writing such a code, we are imitating the functionality provided by the SQL server agent for a SQL server? Think about it. We are scheduling our administrative task by writing custom code – in other words, we have developed a “Light weight SQL server agent for SQL Azure!” Since the SQL server agent is not currently available in cloud, we have developed a solution that enables us to schedule tasks, and thus we have extended SQL Azure with the Azure worker role! Now if you wish to track jobs, you can do so by storing this data in SQL Azure (or Azure tables). The reason is that Windows Azure is a stateless platform, and we will need to store the state of the job ourselves and the choice that you have is SQL Azure or Azure tables. Note that this solution requires custom code and also it is not UI driven; however, for now, it can act as a temporary solution until SQL server agent is made available in the cloud. Moreover, this solution does not encompass functionalities that a SQL server agent provides, but it does open up an interesting avenue to schedule some of the tasks such as backup and synchronization of SQL Azure databases by writing some custom code in the Azure worker role. Now, let us see one more possibility – i.e., running BCP through a worker role in Azure-hosted services and then uploading the backup files either locally or on blobs. If you upload it locally, then consider the data transfer cost. If you upload it to blobs residing in the same datacenter, then no transfer cost applies but the cost on blob size applies. So, before choosing the option, you need to evaluate your preferences keeping the cost associated with each option in mind. In this article, I have shown that Azure worker role solution could be developed to synchronize SQL Azure databases. Moreover, a light-weight SQL server agent for SQL Azure can be developed. Also we discussed the possibility of running BCP through a worker role in Azure-hosted services for backing up our precious SQL Azure data. Thus, we can extend SQL Azure with the Azure worker role. But remember: you will be charged for running Azure worker roles. So at the end of the day, you need to ask – am I willing to build a custom code and pay money to achieve this functionality? I hope you found this blog post interesting. If you have any questions/feedback, you can comment below or you can mail me at Paras[at]student-partners[dot]com Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Azure, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • The importance of Unit Testing in BI

    - by Davide Mauri
    One of the main steps in the process we internally use to develop a BI solution is the implementation of Unit Test of you BI Data. As you may already know, I’ve create a simple (for now) tool that leverages NUnit to allow us to quickly create Unit Testing without having to resort to use Visual Studio Database Professional: http://queryunit.codeplex.com/ Once you have a tool like this one, you can start also to make sure that your BI solution (DWH and CUBE) is not only structurally sound (I mean, the cube or the report gets processed correctly), but you can also check that the logical integrity of your business rules is enforced. For example let’s say that the customer tell you that they will never create an invoice for a specific product-line in 2010 since that product-line is dismissed and will never be sold again. Ok we know that this in theory is true, but a lot of this business rule effectiveness depends on the fact the people does not do a mistake while inserting new orders/invoices and the ERP used implements a check for this business logic. Unfortunately these last two hypotesis are not always true, so you may find yourself really having some invoices for a product line that doesn’t exists anymore. Maybe this kind of situation in future will be solved using Master Data Management but, meanwhile, how you can give and idea of the data quality to your customers? How can you check that logical integrity of the analytical data you produce is exactly what you expect? Well, Unit Testing of a DWH or a CUBE can be a solution. Once you have defined your test suite, by writing SQL and MDX queries that checks that your data is what you expect to be, if you use NUnit (and QueryUnit does), you can then use a tool like NUnit2Report to create a nice HTML report that can be shipped via email to give information of data quality: In addition to that, since NUnit produces an XML file as a result, you can also import it into a SQL Server Database and then monitor the quality of data over time. I’ll be speaking about this approach (and more in general about how to “engineer” a BI solution) at the next European SQL PASS Adaptive BI Best Practices http://www.sqlpass.org/summit/eu2010/Agenda/ProgramSessions/AdaptiveBIBestPratices.aspx I’ll enjoy discussing with you all about this, so see you there! And remember: “if ain't tested it's broken!” (Sorry I don’t remember how said that in first place :-)) Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • Unresolved external symbol __imp____glewGenerateMipmap

    - by Tsvetan
    This error is given by Visual Studio 2010, when I want to compile my C++ code. I have added 'glew32.lib' and 'freeglut.lib' in Additional Dependencies, both release and debug. Also included the header files. I have searched the Internet and found only one forum post, but it isn't the solution I am searching for... My library is dynamic, so GLEW_STATIC is not an option. So, can you give me a solution for this problem?

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  • Scripting with the Sun ZFS Storage 7000 Appliance

    - by Geoff Ongley
    The Sun ZFS Storage 7000 appliance has a user friendly and easy to understand graphical web based interface we call the "BUI" or "Browser User Interface".This interface is very useful for many tasks, but in some cases a script (or workflow) may be more appropriate, such as:Repetitive tasksTasks which work on (or obtain information about) a large number of shares or usersTasks which are triggered by an alert threshold (workflows)Tasks where you want a only very basic input, but a consistent output (workflows)The appliance scripting language is based on ECMAscript 3 (close to javascript). I'm not going to cover ECMAscript 3 in great depth (I'm far from an expert here), but I would like to show you some neat things you can do with the appliance, to get you started based on what I have found from my own playing around.I'm making the assumption you have some sort of programming background, and understand variables, arrays, functions to some extent - but of course if something is not clear, please let me know so I can fix it up or clarify it.Variable Declarations and ArraysVariablesECMAScript is a dynamically and weakly typed language. If you don't know what that means, google is your friend - but at a high level it means we can just declare variables with no specific type and on the fly.For example, I can declare a variable and use it straight away in the middle of my code, for example:projects=list();Which makes projects an array of values that are returned from the list(); function (which is usable in most contexts). With this kind of variable, I can do things like:projects.length (this property on array tells you how many objects are in it, good for for loops etc). Alternatively, I could say:projects=3;and now projects is just a simple number.Should we declare variables like this so loosely? In my opinion, the answer is no - I feel it is a better practice to declare variables you are going to use, before you use them - and given them an initial value. You can do so as follows:var myVariable=0;To demonstrate the ability to just randomly assign and change the type of variables, you can create a simple script at the cli as follows (bold for input):fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("Number of projects is: %d\n",projects.length);("." to run)> projects=152;("." to run)> printf("Value of the projects variable as an integer is now: %d\n",projects);("." to run)> .Number of projects is: 7Value of the projects variable as an integer is now: 152You can also confirm this behaviour by checking the typeof variable we are dealing with:fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> projects=152;("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> .var projects is of type objectvar projects is of type numberArraysSo you likely noticed that we have already touched on arrays, as the list(); (in the shares context) stored an array into the 'projects' variable.But what if you want to declare your own array? Easy! This is very similar to Java and other languages, we just instantiate a brand new "Array" object using the keyword new:var myArray = new Array();will create an array called "myArray".A quick example:fishy10:> script("." to run)> testArray = new Array();("." to run)> testArray[0]="This";("." to run)> testArray[1]="is";("." to run)> testArray[2]="just";("." to run)> testArray[3]="a";("." to run)> testArray[4]="test";("." to run)> for (i=0; i < testArray.length; i++)("." to run)> {("." to run)>    printf("Array element %d is %s\n",i,testArray[i]);("." to run)> }("." to run)> .Array element 0 is ThisArray element 1 is isArray element 2 is justArray element 3 is aArray element 4 is testWorking With LoopsFor LoopFor loops are very similar to those you will see in C, java and several other languages. One of the key differences here is, as you were made aware earlier, we can be a bit more sloppy with our variable declarations.The general way you would likely use a for loop is as follows:for (variable; test-case; modifier for variable){}For example, you may wish to declare a variable i as 0; and a MAX_ITERATIONS variable to determine how many times this loop should repeat:var i=0;var MAX_ITERATIONS=10;And then, use this variable to be tested against some case existing (has i reached MAX_ITERATIONS? - if not, increment i using i++);for (i=0; i < MAX_ITERATIONS; i++){ // some work to do}So lets run something like this on the appliance:fishy10:> script("." to run)> var i=0;("." to run)> var MAX_ITERATIONS=10;("." to run)> for (i=0; i < MAX_ITERATIONS; i++)("." to run)> {("." to run)>    printf("The number is %d\n",i);("." to run)> }("." to run)> .The number is 0The number is 1The number is 2The number is 3The number is 4The number is 5The number is 6The number is 7The number is 8The number is 9While LoopWhile loops again are very similar to other languages, we loop "while" a condition is met. For example:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)>    if (counter==10) ("." to run)>    { ("." to run)>            isTen=true;   ("." to run)>    } ("." to run)>    printf("Counter is %d\n",counter);("." to run)>    counter++;    ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n",counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Counter is 10Loop has ended and Counter is 11So what do we notice here? Something has actually gone wrong - counter will technically be 11 once the loop completes... Why is this?Well, if we have a loop like this, where the 'while' condition that will end the loop may be set based on some other condition(s) existing (such as the counter has reached 10) - we must ensure that we  terminate this iteration of the loop when the condition is met - otherwise the rest of the code will be followed which may not be desirable. In other words, like in other languages, we will only ever check the loop condition once we are ready to perform the next iteration, so any other code after we set "isTen" to be true, will still be executed as we can see it was above.We can avoid this by adding a break into our loop once we know we have set the condition - this will stop the rest of the logic being processed in this iteration (and as such, counter will not be incremented). So lets try that again:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)>    if (counter==10) ("." to run)>    { ("." to run)>            isTen=true;   ("." to run)>            break;("." to run)>    } ("." to run)>    printf("Counter is %d\n",counter);("." to run)>    counter++;    ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n", counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Loop has ended and Counter is 10Much better!Methods to Obtain and Manipulate DataGet MethodThe get method allows you to get simple properties from an object, for example a quota from a user. The syntax is fairly simple:var myVariable=get('property');An example of where you may wish to use this, is when you are getting a bunch of information about a user (such as quota information when in a shares context):var users=list();for(k=0; k < users.length; k++){     user=users[k];     run('select ' + user);     var username=get('name');     var usage=get('usage');     var quota=get('quota');...Which you can then use to your advantage - to print or manipulate infomation (you could change a user's information with a set method, based on the information returned from the get method). The set method is explained next.Set MethodThe set method can be used in a simple manner, similar to get. The syntax for set is:set('property','value'); // where value is a string, if it was a number, you don't need quotesFor example, we could set the quota on a share as follows (first observing the initial value):fishy10:shares default/test-geoff> script("." to run)> var currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> set('quota','30G');("." to run)> run('commit');("." to run)> currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> .Current Quota is: 0Current Quota is: 32212254720This shows us using both the get and set methods as can be used in scripts, of course when only setting an individual share, the above is overkill - it would be much easier to set it manually at the cli using 'set quota=3G' and then 'commit'.List MethodThe list method can be very powerful, especially in more complex scripts which iterate over large amounts of data and manipulate it if so desired. The general way you will use list is as follows:var myVar=list();Which will make "myVar" an array, containing all the objects in the relevant context (this could be a list of users, shares, projects, etc). You can then gather or manipulate data very easily.We could list all the shares and mountpoints in a given project for example:fishy10:shares another-project> script("." to run)> var shares=list();("." to run)> for (i=0; i < shares.length; i++)("." to run)> {("." to run)>    run('select ' + shares[i]);("." to run)>    var mountpoint=get('mountpoint');("." to run)>    printf("Share %s discovered, has mountpoint %s\n",shares[i],mountpoint);("." to run)>    run('done');("." to run)> }("." to run)> .Share and-another discovered, has mountpoint /export/another-project/and-anotherShare another-share discovered, has mountpoint /export/another-project/another-shareShare bob discovered, has mountpoint /export/another-projectShare more-shares-for-all discovered, has mountpoint /export/another-project/more-shares-for-allShare yep discovered, has mountpoint /export/another-project/yepWriting More Complex and Re-Usable CodeFunctionsThe best way to be able to write more complex code is to use functions to split up repeatable or reusable sections of your code. This also makes your more complex code easier to read and understand for other programmers.We write functions as follows:function functionName(variable1,variable2,...,variableN){}For example, we could have a function that takes a project name as input, and lists shares for that project (assuming we're already in the 'project' context - context is important!):function getShares(proj){        run('select ' + proj);        shares=list();        printf("Project: %s\n", proj);        for(j=0; j < shares.length; j++)        {                printf("Discovered share: %s\n",shares[i]);        }        run('done'); // exit selected project}Commenting your CodeLike any other language, a large part of making it readable and understandable is to comment it. You can use the same comment style as in C and Java amongst other languages.In other words, sngle line comments use://at the beginning of the comment.Multi line comments use:/*at the beginning, and:*/ at the end.For example, here we will use both:fishy10:> script("." to run)> // This is a test comment("." to run)> printf("doing some work...\n");("." to run)> /* This is a multi-line("." to run)> comment which I will span across("." to run)> three lines in total */("." to run)> printf("doing some more work...\n");("." to run)> .doing some work...doing some more work...Your comments do not have to be on their own, they can begin (particularly with single line comments this is handy) at the end of a statement, for examplevar projects=list(); // The variable projects is an array containing all projects on the system.Try and Catch StatementsYou may be used to using try and catch statements in other languages, and they can (and should) be utilised in your code to catch expected or unexpected error conditions, that you do NOT wish to stop your code from executing (if you do not catch these errors, your script will exit!):try{  // do some work}catch(err) // Catch any error that could occur{ // do something here under the error condition}For example, you may wish to only execute some code if a context can be reached. If you can't perform certain actions under certain circumstances, that may be perfectly acceptable.For example if you want to test a condition that only makes sense when looking at a SMB/NFS share, but does not make sense when you hit an iscsi or FC LUN, you don't want to stop all processing of other shares you may not have covered yet.For example we may wish to obtain quota information on all shares for all users on a share (but this makes no sense for a LUN):function getShareQuota(shar) // Get quota for each user of this share{        run('select ' + shar);        printf("  SHARE: %s\n", shar);        try        {                run('users');                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","----");                                users=list();                for(k=0; k < users.length; k++)                {                        user=users[k];                        getUserQuota(user);                }                run('done'); // exit user context        }        catch(err)        {                printf("    SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar);        }        run('done'); // done with this share}Running Scripts Remotely over SSHAs you have likely noticed, writing and running scripts for all but the simplest jobs directly on the appliance is not going to be a lot of fun.There's a couple of choices on what you can do here:Create scripts on a remote system and run them over sshCreate scripts, wrapping them in workflow code, so they are stored on the appliance and can be triggered under certain circumstances (like a threshold being reached)We'll cover the first one here, and then cover workflows later on (as these are for the most part just scripts with some wrapper information around them).Creating a SSH Public/Private SSH Key PairLog on to your handy Solaris box (You wouldn't be using any other OS, right? :P) and use ssh-keygen to create a pair of ssh keys. I'm storing this separate to my normal key:[geoff@lightning ~] ssh-keygen -t rsa -b 1024Generating public/private rsa key pair.Enter file in which to save the key (/export/home/geoff/.ssh/id_rsa): /export/home/geoff/.ssh/nas_key_rsaEnter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /export/home/geoff/.ssh/nas_key_rsa.Your public key has been saved in /export/home/geoff/.ssh/nas_key_rsa.pub.The key fingerprint is:7f:3d:53:f0:2a:5e:8b:2d:94:2a:55:77:66:5c:9b:14 geoff@lightningInstalling the Public Key on the ApplianceOn your Solaris host, observe the public key:[geoff@lightning ~] cat .ssh/nas_key_rsa.pub ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc= geoff@lightningNow, copy and paste everything after "ssh-rsa" and before "user@hostname" - in this case, geoff@lightning. That is, this bit:AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc=Logon to your appliance and get into the preferences -> keys area for this user (root):[geoff@lightning ~] ssh [email protected]: Last login: Mon Dec  6 17:13:28 2010 from 192.168.0.2fishy10:> configuration usersfishy10:configuration users> select rootfishy10:configuration users root> preferences fishy10:configuration users root preferences> keysOR do it all in one hit:fishy10:> configuration users select root preferences keysNow, we create a new public key that will be accepted for this user and set the type to RSA:fishy10:configuration users root preferences keys> createfishy10:configuration users root preferences key (uncommitted)> set type=RSASet the key itself using the string copied previously (between ssh-rsa and user@host), and set the key ensuring you put double quotes around it (eg. set key="<key>"):fishy10:configuration users root preferences key (uncommitted)> set key="AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc="Now set the comment for this key (do not use spaces):fishy10:configuration users root preferences key (uncommitted)> set comment="LightningRSAKey" Commit the new key:fishy10:configuration users root preferences key (uncommitted)> commitVerify the key is there:fishy10:configuration users root preferences keys> lsKeys:NAME     MODIFIED              TYPE   COMMENT                                  key-000  2010-10-25 20:56:42   RSA    cycloneRSAKey                           key-001  2010-12-6 17:44:53    RSA    LightningRSAKey                         As you can see, we now have my new key, and a previous key I have created on this appliance.Running your Script over SSH from a Remote SystemHere I have created a basic test script, and saved it as test.ecma3:[geoff@lightning ~] cat test.ecma3 script// This is a test script, By Geoff Ongley 2010.printf("Testing script remotely over ssh\n");.Now, we can run this script remotely with our keyless login:[geoff@lightning ~] ssh -i .ssh/nas_key_rsa root@fishy10 < test.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Testing script remotely over sshPutting it Together - An Example Completed Quota Gathering ScriptSo now we have a lot of the basics to creating a script, let us do something useful, like, find out how much every user is using, on every share on the system (you will recognise some of the code from my previous examples): script/************************************** Quick and Dirty Quota Check script ** Written By Geoff Ongley            ** 25 October 2010                    **************************************/function getUserQuota(usr){        run('select ' + usr);        var username=get('name');        var usage=get('usage');        var quota=get('quota');        var usage_g=usage / 1073741824; // convert bytes to gigabytes        var quota_g=quota / 1073741824; // as above        var quota_percent=0        if (quota > 0)        {                quota_percent=(usage / quota)*(100/1);        }        printf("    %20s        %8.2f           %8.2f           %d%%\n",username,usage_g,quota_g,quota_percent);        run('done'); // done with this selected user}function getShareQuota(shar){        //printf("DEBUG: selecting share %s\n", shar);        run('select ' + shar);        printf("  SHARE: %s\n", shar);        try        {                run('users');                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","--------");                                users=list();                for(k=0; k < users.length; k++)                {                        user=users[k];                        getUserQuota(user);                }                run('done'); // exit user context        }        catch(err)        {                printf("    SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar);        }        run('done'); // done with this share}function getShares(proj){        //printf("DEBUG: selecting project %s\n",proj);        run('select ' + proj);        shares=list();        printf("Project: %s\n", proj);        for(j=0; j < shares.length; j++)        {                share=shares[j];                getShareQuota(share);        }        run('done'); // exit selected project}function getProjects(){        run('cd /');        run('shares');        projects=list();                for (i=0; i < projects.length; i++)        {                var project=projects[i];                getShares(project);        }        run('done'); // exit context for all projects}getProjects();.Which can be run as follows, and will print information like this:[geoff@lightning ~/FISHWORKS_SCRIPTS] ssh -i ~/.ssh/nas_key_rsa root@fishy10 < get_quota_utilisation.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Project: another-project  SHARE: and-another                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                  nobody            0.00            0.00        0%                 geoffro            0.05            0.00        0%                   Billy            0.10            0.00        0%                    root            0.00            0.00        0%            testing-user            0.05            0.00        0%  SHARE: another-share                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                    root            0.00            0.00        0%                  nobody            0.00            0.00        0%                 geoffro            0.05            0.49        9%            testing-user            0.05            0.02        249%                   Billy            0.10            0.29        33%  SHARE: bob                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                  nobody            0.00            0.00        0%                    root            0.00            0.00        0%  SHARE: more-shares-for-all                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                   Billy            0.10            0.00        0%            testing-user            0.05            0.00        0%                  nobody            0.00            0.00        0%                    root            0.00            0.00        0%                 geoffro            0.05            0.00        0%  SHARE: yep                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                    root            0.00            0.00        0%                  nobody            0.00            0.00        0%                   Billy            0.10            0.01        999%            testing-user            0.05            0.49        9%                 geoffro            0.05            0.00        0%Project: default  SHARE: Test-LUN    SKIPPING Test-LUN - This is NOT a NFS or CIFs share, not looking for users  SHARE: test-geoff                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                 geoffro            0.05            0.00        0%                    root            3.18           10.00        31%                    uucp            0.00            0.00        0%                  nobody            0.59            0.49        119%^CKilled by signal 2.Creating a WorkflowWorkflows are scripts that we store on the appliance, and can have the script execute either on request (even from the BUI), or on an event such as a threshold being met.Workflow BasicsA workflow allows you to create a simple process that can be executed either via the BUI interface interactively, or by an alert being raised (for some threshold being reached, for example).The basics parameters you will have to set for your "workflow object" (notice you're creating a variable, that embodies ECMAScript) are as follows (parameters is optional):name: A name for this workflowdescription: A Description for the workflowparameters: A set of input parameters (useful when you need user input to execute the workflow)execute: The code, the script itself to execute, which will be function (parameters)With parameters, you can specify things like this (slightly modified sample taken from the System Administration Guide):          ...parameters:        variableParam1:         {                             label: 'Name of Share',                             type: 'String'                  },                  variableParam2                  {                             label: 'Share Size',                             type: 'size'                  },execute: ....};  Note the commas separating the sections of name, parameters, execute, and so on. This is important!Also - there is plenty of properties you can set on the parameters for your workflow, these are described in the Sun ZFS Storage System Administration Guide.Creating a Basic Workflow from a Basic ScriptTo make a basic script into a basic workflow, you need to wrap the following around your script to create a 'workflow' object:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function() {// (basic script goes here, minus the "script" at the beginning, and "." at the end)}};However, it appears (at least in my experience to date) that the workflow object may only be happy with one function in the execute parameter - either that or I'm doing something wrong. As far as I can tell, after execute: you should only have a basic one function context like so:execute: function(){}To deal with this, and to give an example similar to our script earlier, I have created another simple quota check, to show the same basic functionality, but in a workflow format:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function () {        run('cd /');        run('shares');        projects=list();                for (i=0; i < projects.length; i++)        {                run('select ' + projects[i]);                shares=list('filesystem');                printf("Project: %s\n", projects[i]);                for(j=0; j < shares.length; j++)                {                        run('select ' +shares[j]);                        try                        {                                run('users');                                printf("  SHARE: %s\n", shares[j]);                                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","-------");                                users=list();                                for(k=0; k < users.length; k++)                                {                                        run('select ' + users[k]);                                        username=get('name');                                        usage=get('usage');                                        quota=get('quota');                                        usage_g=usage / 1073741824; // convert bytes to gigabytes                                        quota_g=quota / 1073741824; // as above                                        quota_percent=0                                        if (quota > 0)                                        {                                                quota_percent=(usage / quota)*(100/1);                                        }                                        printf("    %20s        %8.2f   %8.2f   %d%%\n",username,usage_g,quota_g,quota_percent);                                        run('done');                                }                                run('done'); // exit user context                        }                        catch(err)                        {                        //      printf("    %s is a LUN, Not looking for users\n", shares[j]);                        }                        run('done'); // exit selected share context                }                run('done'); // exit project context        }        }};SummaryThe Sun ZFS Storage 7000 Appliance offers lots of different and interesting features to Sun/Oracle customers, including the world renowned Analytics. Hopefully the above will help you to think of new creative things you could be doing by taking advantage of one of the other neat features, the internal scripting engine!Some references are below to help you continue learning more, I'll update this post as I do the same! Enjoy...More information on ECMAScript 3A complete reference to ECMAScript 3 which will help you learn more of the details you may be interested in, can be found here:http://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-262,%203rd%20edition,%20December%201999.pdfMore Information on Administering the Sun ZFS Storage 7000The Sun ZFS Storage 7000 System Administration guide can be a useful reference point, and can be found here:http://wikis.sun.com/download/attachments/186238602/2010_Q3_2_ADMIN.pdf

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  • Transposition - the success story of VB6 migration

    - by Visual WebGui
    Since all of you VB developers in the present or past would probably find it hard to believe that the old VB code can be migrated and modernized into the latest .NET based HTML5 without having to rewrite the application I am feeling I need to write another post on our migration solution. Hopefully, after reading this and the previous post you will be able to understand the different approach of our solution which already helps organizations around the world move away from the constraints of VB6 and...(read more)

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