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  • Ruby Dir.glob works on laptop not on desktop?

    - by Nick Faraday
    I have a ruby shell script that works perfectly on my laptop, but Dir.glob doesn't seem to work when I try and run it on my desktop. Here is the code: sFileTemplate = File.join("**", sResolutions, "**", "*."+sType) sFiles = Dir.glob(sFileTemplate) Both machines run OSX 10.5 and are running ruby -v 1.9.1. Am I calling glob wrong? Thanks

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  • Is there any memory restrictions on an ASP.Net application? HttpHandler?

    - by tpower
    I have an ASP.Net MVC application that allows users to upload images. When I try to upload a really large file (400MB) I get an error. I assumed that my image processing code (home brew) was very inefficient, so I decided I would try using a third party library to handle the image processing parts. Because I'm using TDD, I wanted to first write a test that fails. But when I test the controller action with the same large file it is able to do all the image processing without any trouble. The error I get is "Out of memory". I'm sure my code is probably using a lot more memory than it needs to but I just want to know why my test passes. The other difference is that I'm using SWFUpload which is not used with the test. Could this be the cause?

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  • Can I have Sinatra / Rack not read the entire request body into memory?

    - by Chris Markle
    Say I have a Sinatra route ala: put '/data' do request.body.read # ... end It appears that the entire request.body is read into memory. Is there a way to consume the body as it comes into the system, rather than having it all buffered in Rack/Sinatra beforehand? I see I can do this to read the body in parts, but the entire body still seems to be read into memory beforehand. put '/data' do while request.body.read(1024) != nil # ... end # ... end

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  • Hold most of the object in cache/memory insted of database?

    - by feiroox
    Hi All, It just occurred to me why not to have most of the objects in a cache(memory) when an application start. if it's not that large web application. Or to have a settings for how much I want to put in the cache/memory. I just guess it could require to have something like below 1 GB RAM or a lot less. Everything in order to speed up the application even more by not querying database. Is it good idea?

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  • Is Memory increase create difference in output or behavior of java application?

    - by Nitz
    Hey Guys I have created one java-swing application. The application runs perfectly runs perfect on my pc. But it doesn't run perfectly on client pc. I had increase my Virtual Memory, earlier on my pc. So my question is.. Is changing memory limit, effect or change application behavior? Is there anything that change the behavior of java application? bcz same application runs perfectly on my pc and same application does not running perfectly on client pc? and there is no problem in code, i have checked three times.

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  • Recursive MySQL function call eats up too much memory and dies.

    - by kylex
    I have the following recursive function which works... up until a point. Then the script asks for more memory once the queries exceed about 100, and when I add more memory, the script typically just dies (I end up with a white screen on my browser). public function returnPArray($parent=0,$depth=0,$orderBy = 'showOrder ASC'){ $query = mysql_query("SELECT *, UNIX_TIMESTAMP(lastDate) AS whenTime FROM these_pages WHERE parent = '".$parent."' AND deleted = 'N' ORDER BY ".$orderBy.""); $rows = mysql_num_rows($query); while($row = mysql_fetch_assoc($query)){ // This uses my class and places the content in an array. MyClass::$_navArray[] = array( 'id' => $row['id'], 'parent' => $row['parent'] ); MyClass::returnPArray($row['id'],($depth+1)); } $i++; } Can anyone help me make this query less resource intensive?

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  • How SQL Server 2014 impacts Red Gate’s SQL Compare

    - by Michelle Taylor
    SQL Compare 10.7 successfully connects to SQL Server 2014, but it doesn’t yet cover the SQL Server 2014 features which would require us to make major changes to SQL Compare to support. In this post I’m going to talk about the SQL Server 2014 features we’ve already begun supporting, and which ones we’re working on for the next release of SQL Compare (v11). From SQL Compare’s perspective, the new memory-optimized table functionality (some might know it as ‘Hekaton’) has been the most important change. It can’t be described as its own object type, but the new functionality is split across two existing object types (three if you count indexes), as it also comes with native stored procedures and inline indexes. Along with connectivity support, the SQL Compare team has already implemented the first part of the puzzle – inline specification of indexes. These are essential for memory-optimized tables because it’s not possible to alter the memory optimized table’s structure, and so indexes can’t be added after the fact without dropping the table. Books Online  shows this in more detail in the table_index and column_index clauses of http://msdn.microsoft.com/en-us/library/ms174979(v=sql.120).aspx. SQL Compare 10.7 currently supports reading the new inline index specification from script folders and source control repositories, and will write out inline indexes where it’s necessary to do so (i.e. in UDDTs or when attempting to write projects compatible with the SSDT database project format). However, memory-optimized tables themselves are not yet supported in 10.7. The team is actively working on making them available in the v11 release with full support later in the year, and in a beta version before that. Fortunately, SQL Compare already has some ways of handling tables that have to be dropped and created rather than altered, which are being adapted to handle this new kind of table. Because it’s one of the largest new database engine features, there’s an equally large Books Online section on memory-optimized tables, but for us the most important parts of the documentation are the normal table features that are changed or unsupported and the new syntax found in the T-SQL reference pages. We are treating SQL Compare’s support of Natively Compiled Stored Procedures as a separate unit of work, which will be available in a subsequent beta and also feed into the v11 release. This new type of stored procedure is designed to work with memory-optimized tables to maintain the performance improvements gained by them – but you can still also access memory-optimized tables from normal stored procedures and ad-hoc queries. To us, they’re essentially a limited-syntax stored procedure with a few extra options in the create statement, embodied in the updated CREATE PROCEDURE documentation and with the detailed limitations. They should be easier to handle than memory-optimized tables simply because the handling of stored procedures is less sensitive to dropping the object than the handling of tables. However, both share an incompatibility with DDL triggers and Event Notifications which mean we’ll need to temporarily disable these during the specific deployment operations that involve them – don’t worry, we’ll supply a warning if this is the case so that you can check your auditing arrangements can handle the situation. There are also a handful of other improvements in SQL Server 2014 which affect SQL Compare and SQL Data Compare that are not connected to memory optimized tables. The largest of these are the improvements to columnstore indexes, with the capability to create clustered columnstore indexes and update columnstore tables through them – for more detail, take a look at the new syntax reference. There’s also a new index option for better compression of columnstores (COLUMNSTORE_ARCHIVE) and a new statistics option for incremental per-partition statistics, plus the 90 compatibility level is being retired. We’re planning to finish up these small clean-up features last, and be ready to release SQL Compare 11 with full SQL 2014 support early in Q3 this year. For a more thorough overview of what’s new in SQL Server 2014, Books Online’s What’s New section is a good place to start (although almost all the changes in this version are in the Database Engine).

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  • ORA-4031 Troubleshooting

    - by [email protected]
      QUICKLINK: Note 396940.1 Troubleshooting and Diagnosing ORA-4031 Error Note 1087773.1 : ORA-4031 Diagnostics Tools [Video]   Have you observed an ORA-04031 error reported in your alert log? An ORA-4031 error is raised when memory is unavailable for use or reuse in the System Global Area (SGA).  The error message will indicate the memory pool getting errors and high level information about what kind of allocation failed and how much memory was unavailable.  The challenge with ORA-4031 analysis is that the error and associated trace is for a "victim" of the problem.   The failing code ran into the memory limitation, but in almost all cases it was not part of the root problem.    Looking for the best way to diagnose? When an ORA-4031 error occurs, a trace file is raised and noted in the alert log if the process experiencing the error is a background process.   User processes may experience errors without reports in the alert log or traces generated.   The V$SHARED_POOL_RESERVED view will show reports of misses for memory over the life of the database. Diagnostics scripts are available in Note 430473.1 to help in analysis of the problem.  There is also a training video on using and interpreting the script data Note 1087773.1. 11g DiagnosabilityStarting with Oracle Database 11g Release 1, the Diagnosability infrastructure was introduced which places traces and core files into a location controlled by the DIAGNOSTIC_DEST initialization parameter when an incident, such as an ORA-4031 occurs. For earlier versions, the trace file will be written to either USER_DUMP_DEST (if the error was caught in a user process) or BACKGROUND_DUMP_DEST (if the error was caught in a background process like PMON or SMON). The trace file contains vital information about what led to the error condition.  Note 443529.1 11g Quick Steps to Package and Send Critical Error Diagnostic Information to Support[Video]Oracle Configuration Manager (OCM)Oracle Configuration Manager (OCM) works with My Oracle Support to enable proactive support capability that helps you organize, collect and manage your Oracle configurations.Oracle Configuration Manager Quick Start GuideNote 548815.1: My Oracle Support Configuration Management FAQ Note 250434.1: BULLETIN: Learn More About My Oracle Support Configuration Manager    Common Causes/Solutions The ORA-4031 can occur for many different reasons.  Some possible causes are: SGA components too small for workload Auto-tuning issues Fragmentation due to application design Bug/leaks in memory allocationsFor more on the 4031 and how this affects the SGA, see Note 396940.1 Troubleshooting and Diagnosing ORA-4031 Error Because of the multiple potential causes, it is important to gather enough diagnostics so that an appropriate solution can be identified.  However, most commonly the cause is associated with configuration tuning.   Ensuring that MEMORY_TARGET or SGA_TARGET are large enough to accommodate workload can get around many scenarios.  The default trace associated with the error provides very high level information about the memory problem and the "victim" that ran into the issue.   The data in the default trace is not going to point to the root cause of the problem. When migrating from 9i to 10g and higher, it is necessary to increase the size of the Shared Pool due to changes in the basic design of the shared memory area. Note 270935.1 Shared pool sizing in 10gNOTE: Diagnostics on the errors should be investigated as close to the time of the error(s) as possible.  If you must restart a database, it is not feasible to diagnose the problem until the database has matured and/or started seeing the problems again. Note 801787.1 Common Cause for ORA-4031 in 10gR2, Excess "KGH: NO ACCESS" Memory Allocation ***For reference to the content in this blog, refer to Note.1088239.1 Master Note for Diagnosing ORA-4031 

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  • installer can't find partition, but fdisk can find them

    - by pxd
    I'm installing ubuntu 12.04, my system had install 2 system -- winxp and ubuntu 10.10. Now, I want to update ubuntu to 12.04. I use usb disk to install 12.04. But, the installer can't not find my partition in my harddisk. But, the fdisk can find them. Can you help me? How to do? ubuntu@ubuntu:~$ sudo lshw -short H/W path Device Class Description system HP 2230s (NN868PA#AB2) /0 bus 3037 /0/9 memory 64KiB BIOS /0/0 processor Intel(R) Core(TM)2 Duo CPU T6570 @ 2.10GHz /0/0/1 memory 2MiB L2 cache /0/0/3 memory 32KiB L1 cache /0/0/0.1 processor Logical CPU /0/0/0.2 processor Logical CPU /0/2 memory 32KiB L1 cache /0/4 memory 2GiB System Memory /0/4/0 memory SODIMM [empty] /0/4/1 memory 2GiB SODIMM DDR2 Synchronous 800 MHz (1.2 ns) /0/100 bridge Mobile 4 Series Chipset Memory Controller Hub /0/100/2 display Mobile 4 Series Chipset Integrated Graphics Controller /0/100/2.1 display Mobile 4 Series Chipset Integrated Graphics Controller /0/100/1a bus 82801I (ICH9 Family) USB UHCI Controller #4 /0/100/1a.1 bus 82801I (ICH9 Family) USB UHCI Controller #5 /0/100/1a.2 bus 82801I (ICH9 Family) USB UHCI Controller #6 /0/100/1a.7 bus 82801I (ICH9 Family) USB2 EHCI Controller #2 /0/100/1b multimedia 82801I (ICH9 Family) HD Audio Controller /0/100/1c bridge 82801I (ICH9 Family) PCI Express Port 1 /0/100/1c.1 bridge 82801I (ICH9 Family) PCI Express Port 2 /0/100/1c.1/0 wlan1 network PRO/Wireless 5100 AGN [Shiloh] Network Connection /0/100/1c.2 bridge 82801I (ICH9 Family) PCI Express Port 3 /0/100/1c.4 bridge 82801I (ICH9 Family) PCI Express Port 5 /0/100/1c.5 bridge 82801I (ICH9 Family) PCI Express Port 6 /0/100/1c.5/0 eth1 network 88E8072 PCI-E Gigabit Ethernet Controller /0/100/1d bus 82801I (ICH9 Family) USB UHCI Controller #1 /0/100/1d.1 bus 82801I (ICH9 Family) USB UHCI Controller #2 /0/100/1d.2 bus 82801I (ICH9 Family) USB UHCI Controller #3 /0/100/1d.7 bus 82801I (ICH9 Family) USB2 EHCI Controller #1 /0/100/1e bridge 82801 Mobile PCI Bridge /0/100/1f bridge ICH9M LPC Interface Controller /0/100/1f.2 scsi0 storage 82801IBM/IEM (ICH9M/ICH9M-E) 4 port SATA Controller [AHCI mode] /0/100/1f.2/0 /dev/sda disk 500GB WDC WD5000BEVT-0 /0/100/1f.2/0/1 /dev/sda1 volume 48GiB Windows NTFS volume /0/100/1f.2/0/2 /dev/sda2 volume 416GiB Extended partition /0/100/1f.2/0/2/5 /dev/sda5 volume 97GiB HPFS/NTFS partition /0/100/1f.2/0/2/6 /dev/sda6 volume 198GiB HPFS/NTFS partition /0/100/1f.2/0/2/7 /dev/sda7 volume 27GiB Linux filesystem partition /0/100/1f.2/0/2/8 /dev/sda8 volume 93GiB Linux filesystem partition /0/100/1f.2/1 /dev/cdrom disk CDDVDW TS-L633M /0/1 scsi6 storage /0/1/0.0.0 /dev/sdb disk 15GB STORAGE DEVICE /0/1/0.0.0/0 /dev/sdb disk 15GB /0/1/0.0.0/0/1 /dev/sdb1 volume 14GiB Windows FAT volume /1 power HZ04037 ubuntu@ubuntu:~$ ubuntu@ubuntu:~$ sudo fdisk -l Disk /dev/sda: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x31263125 Device Boot Start End Blocks Id System /dev/sda1 * 63 102277727 51138832+ 7 HPFS/NTFS/exFAT /dev/sda2 102277728 976784129 437253201 f W95 Ext'd (LBA) /dev/sda5 102277791 307078127 102400168+ 7 HPFS/NTFS/exFAT /dev/sda6 307078191 724141151 208531480+ 7 HPFS/NTFS/exFAT /dev/sda7 724142080 781459455 28658688 83 Linux /dev/sda8 781461504 976771071 97654784 83 Linux Disk /dev/sdb: 15.9 GB, 15931539456 bytes 64 heads, 32 sectors/track, 15193 cylinders, total 31116288 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0009eb92 Device Boot Start End Blocks Id Systemfile:///home/ubuntu/Pictures/Screenshot%20from%202012-07-07%2010:25:40.png /dev/sdb1 * 32 31115263 15557616 c W95 FAT32 (LBA) ubuntu 12.04 installer can't find the partition in my hard disk, only find device - /dev/sda.(sorry, I'm new user, so can't send image.)

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  • Error cloning gitosis-admin on new setup

    - by michaelmior
    I have the following in my gitosis.conf. (Created via gitsosis-init < id_rsa.pub with the key from my laptop) [gitosis] loglevel = DEBUG [group gitosis-admin] writable = gitosis-admin members = michael@laptop When I try git clone git@SERVER:gitsos-admin.git, I get the following errors: Initialized empty Git repository in /home/michael/gitsos-admin/.git/ DEBUG:gitosis.serve.main:Got command "git-upload-pack 'gitsos-admin.git'" DEBUG:gitosis.access.haveAccess:Access check for 'michael@laptop' as 'writable' on 'gitsos-admin.git'... DEBUG:gitosis.access.haveAccess:Stripping .git suffix from 'gitsos-admin.git', new value 'gitsos-admin' DEBUG:gitosis.group.getMembership:found 'michael@laptop' in 'gitosis-admin' DEBUG:gitosis.access.haveAccess:Access check for 'michael@laptop' as 'writeable' on 'gitsos-admin.git'... DEBUG:gitosis.access.haveAccess:Stripping .git suffix from 'gitsos-admin.git', new value 'gitsos-admin' DEBUG:gitosis.group.getMembership:found 'michael@laptop' in 'gitosis-admin' DEBUG:gitosis.access.haveAccess:Access check for 'michael@laptop' as 'readonly' on 'gitsos-admin.git'... DEBUG:gitosis.access.haveAccess:Stripping .git suffix from 'gitsos-admin.git', new value 'gitsos-admin' DEBUG:gitosis.group.getMembership:found 'michael@laptop' in 'gitosis-admin' ERROR:gitosis.serve.main:Repository read access denied fatal: The remote end hung up unexpectedly I know my key is being accepted because I have tried logging in via SSH and although a terminal won't be allocated, the authorization works.

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  • Will Parallel-port dongle work on USB-to-Parallel Adapter?

    - by Gary M. Mugford
    We have a niche program running on a Win2K laptop that uses a security dongle connected to a parallel port for authentication. The laptop is getting creaky and I spent a frustrating night last night shopping various websites for a new laptop that had a parallel port. Seems I'm about three years late [G]. The question I have, is, if I buy a new(ish) laptop and use a USB-to-Parallel Port adapter, will the security dongle work? I know I'm not being specific about the app, but it's one most people wouldn't have heard of anyways. I've been guessing the answer to my question is no, since the app won't know to send a request out to the non-existent port. But, if the process actually is that the dongle sends a message INTO the computer every now and then, then it might work. And, I'm not sure whether the dongle is only needed at program startup time or randomly. The dongle is a 'permanent' addition to the old laptop. This is all about the money. We can have a newly-updated version of the program (which won't add any features we need) for the princely sum of $2700. Or we can spend $500 on a refurbed laptop still running WinXP, add a 30 buck adapter and keep the same solid, stolid performance we've come to appreciate. But it all comes down to the dongle behaviour. Oh, and a dock won't work. The whole laptop issue is about moving about the various nooks and crannies of the building with laptop in hand. Thanks for any suggestions/guidance. GM

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  • Hard drive degredation from large memory usage and paging files?

    - by Stephen R
    I've had a question(s) regarding computer degradation going through my head for a while and haven't found many good resources for researching it. 1) First off, when is the virtual RAM/paging file on a hard drive used by Windows? Is it used when the RAM is full? Or does it use the Virtual RAM/paging file as intermediate caching between the RAM and actual hard drive space all the time? 2) If I were to run many applications on my computer at the same time and have a bad habit of doing this for the entire lifetime of the computer, does it use more of the virtual RAM/paging file than if I were to have fewer programs running? Just to note, the RAM never fills up on my computer but it is used heavily. 3) By extension of question 2, if the virtual RAM/paging file is used more heavily, would that result in rapid hard drive degradation? I have seen a pattern among all of the computers that I have owned or used in the past 5 years. I am the kind of person to leave my web browser up with 40 tabs among other programs which will eat up 40% of my memory typically. Over time my computer will slow down, browsers start crashing, programs start seizing up or crashing themselves, eventually the computer becomes essentially unusable. I have been trying to rack my mind to come up with a solution other than to purchase a new PC to have it die on me in the next couple years as well. This is the only thought that has come to mind that might have a simple hardware fix...Windows ReadyBoost...Maybe? I'd like to be able to discuss this so I can learn something about all of the above. Thanks.

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  • HP dv6910 laptop no longer recognizes wireless adapter, dvd drive, and one usb port. What can I do about this?

    - by Joan H.
    In the last 3 weeks, my not even 3 year old HP laptop (vista) just seems to be failing. First, one of the usb ports stopped working. Next, the dvd drive all of a sudden was not recognized as even existing, so it is now useless. And as of today, I no longer seem to have a wireless adapter on my laptop. It doesn't show up in device manager, same as the dvd drive. I can connect to the internet by ethernet cable, but not wirelessly. It worked fine last night; now it doesn't even exist! I have tried a 'hard reset' I read about on HP's forum- no help. I am not sure what else to try. I read about the USB wifi dongle in another response, but I already have maxed our my usb ports even though I have bought a USB hub since the one port failed. Plus, I'd like my laptop to just work like it's supposed to instead of being jerry rigged with usb hubs, external dvd drives, and wifi dongles etc. Any ideas?

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  • CentOS server. What does it mean when the total used RAM does not equal the sum of RES?

    - by Michael Green
    I'm having a problem with a virtual hosted server running CentOS. In the past month a process (java based) that had been running fine started having problems getting memory when the JVM was started. One strange thing I've noticed is that when I start the process, the PID says it is using 470mb of RAM while the 'used' memory immediately drops by over a 1GB. If I run 'top', the total RES used across all processes falls short of the 'used' listed at the top by almost 700mb. The support person says this means I have a memory leak with my process. I don't know what to believe because I would expect a memory leak to simply waste the memory the process is allocated not to consume additional memory that doesn't show up using 'top'. I'm a developer and not a server guy so I'm appealing to the experts. To me, if the total RES memory doesn't add up to the total 'used' it indicates that something is wrong with my virtual server set-up. Would you also suspect a memory leaking java process in this case? If I use free before: total used free shared buffers cached Mem: 2097152 149264 1947888 0 0 0 -/+ buffers/cache: 149264 1947888 Swap: 0 0 0 free after: total used free shared buffers cached Mem: 2097152 1094116 1003036 0 0 0 -/+ buffers/cache: 1094116 1003036 Swap: 0 0 0 So it looks as though the process is using (or causing to be used) nearly 1GB of RAM. Since the process (based on top is only using 452mb, does that mean that the kernal is all of a sudden using an additional 500mb?

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  • Killing a process which ran for a lot of time or is using a lot of memory

    - by Vedant Terkar
    I am not sure whether this question belong to Stack Overflow or here, but here we go. I am designing a online 'C' compiler, which will compile and invoke the program if compilation succeeded. So here is code which I am using for that: $str=shell_exec("gcc path/to/file.c -o path/to/file.exe 2>&1"); if(file_exists("path/to/file.exe")){ $res=shell_exec("path/to/file.exe <inputfile 2>&1"); echo $res; } This Seems to work fine with simple program files. But When file.c That is the source code entered contains Infinite loop then This script crashes the server and utilizes a lot of memory and time. So here is my question: Is There any way to detect for how much time does the process file.exe is Running? How Much Space is Utilized by that process that is file.exe? Is There any way to kill the process file.exe if space and time utilization increases beyond certain limit? That Mean if we allocate time of 2.5sec and space of 40Mb at max for that process file.exe and if any one of those 2 constraints is violated then we should display appropriate error message to client Is it possible? I am Using WAMP (Windows 7).

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  • Question marks showing in ls of directory. IO errors too.

    - by jaymoo
    Has anyone seen this before? I've got a raid 5 mounted on my server and for whatever reason it started showing this: jason@box2:/mnt/raid1/cra$ ls -alh ls: cannot access e6eacc985fea729b2d5bc74078632738: Input/output error ls: cannot access 257ad35ee0b12a714530c30dccf9210f: Input/output error total 0 drwxr-xr-x 5 root root 123 2009-08-19 16:33 . drwxr-xr-x 3 root root 16 2009-08-14 17:15 .. ?????????? ? ? ? ? ? 257ad35ee0b12a714530c30dccf9210f drwxr-xr-x 3 root root 57 2009-08-19 16:58 9c89a78e93ae6738e01136db9153361b ?????????? ? ? ? ? ? e6eacc985fea729b2d5bc74078632738 The md5 strings are actual directory names and not part of the error. The question marks are odd, and any directory with a question mark throws an io error when you attempt to use/delete/etc it. I was unable to umount the drive due to "busy". Rebooting the server "fixed" it but it was throwing some raid errors on shutdown. I have configured two raid 5 arrays and both started doing this on random files. Both are using the following config: mkfs.xfs -l size=128m -d agcount=32 mount -t xfs -o noatime,logbufs=8 Nothing too fancy, but part of an optimized config for this box. We're not partitioning the drives and that was suggested as a possible issue. Could this be the culprit?

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  • Load and Web Performance Testing using Visual Studio Ultimate 2010-Part 3

    - by Tarun Arora
    Welcome back once again, in Part 1 of Load and Web Performance Testing using Visual Studio 2010 I talked about why Performance Testing the application is important, the test tools available in Visual Studio Ultimate 2010 and various test rig topologies, in Part 2 of Load and Web Performance Testing using Visual Studio 2010 I discussed the details of web performance & load tests as well as why it’s important to follow a goal based pattern while performance testing your application. In part 3 I’ll be discussing Test Result Analysis, Test Result Drill through, Test Report Generation, Test Run Comparison, Asp.net Profiler and some closing thoughts. Test Results – I see some creepy worms! In Part 2 we put together a web performance test and a load test, lets run the test to see load test to see how the Web site responds to the load simulation. While the load test is running you will be able to see close to real time analysis in the Load Test Analyser window. You can use the Load Test Analyser to conduct load test analysis in three ways: Monitor a running load test - A condensed set of the performance counter data is maintained in memory. To prevent the results memory requirements from growing unbounded, up to 200 samples for each performance counter are maintained. This includes 100 evenly spaced samples that span the current elapsed time of the run and the most recent 100 samples.         After the load test run is completed - The test controller spools all collected performance counter data to a database while the test is running. Additional data, such as timing details and error details, is loaded into the database when the test completes. The performance data for a completed test is loaded from the database and analysed by the Load Test Analyser. Below you can see a screen shot of the summary view, this provides key results in a format that is compact and easy to read. You can also print the load test summary, this is generated after the test has completed or been stopped.         Analyse the load test results of a previously run load test – We’ll see this in the section where i discuss comparison between two test runs. The performance counters can be plotted on the graphs. You also have the option to highlight a selected part of the test and view details, drill down to the user activity chart where you can hover over to see more details of the test run.   Generate Report => Test Run Comparisons The level of reports you can generate using the Load Test Analyser is astonishing. You have the option to create excel reports and conduct side by side analysis of two test results or to track trend analysis. The tools also allows you to export the graph data either to MS Excel or to a CSV file. You can view the ASP.NET profiler report to conduct further analysis as well. View Data and Diagnostic Attachments opens the Choose Diagnostic Data Adapter Attachment dialog box to select an adapter to analyse the result type. For example, you can select an IntelliTrace adapter, click OK and open the IntelliTrace summary for the test agent that was used in the load test.   Compare results This creates a set of reports that compares the data from two load test results using tables and bar charts. I have taken these screen shots from the MSDN documentation, I would highly recommend exploring the wealth of knowledge available on MSDN. Leaving Thoughts While load testing the application with an excessive load for a longer duration of time, i managed to bring the IIS to its knees by piling up a huge queue of requests waiting to be processed. This clearly means that the IIS had run out of threads as all the threads were busy processing existing request, one easy way of fixing this is by increasing the default number of allocated threads, but this might escalate the problem. The better suggestion is to try and drill down to the actual root cause of the problem. When ever the garbage collection runs it stops processing any pages so all requests that come in during that period are queued up, but realistically the garbage collection completes in fraction of a a second. To understand this better lets look at the .net heap, it is divided into large heap and small heap, anything greater than 85kB in size will be allocated to the Large object heap, the Large object heap is non compacting and remember large objects are expensive to move around, so if you are allocating something in the large object heap, make sure that you really need it! The small object heap on the other hand is divided into generations, so all objects that are supposed to be short-lived are suppose to live in Gen-0 and the long living objects eventually move to Gen-2 as garbage collection goes through.  As you can see in the picture below all < 85 KB size objects are first assigned to Gen-0, when Gen-0 fills up and a new object comes in and finds Gen-0 full, the garbage collection process is started, the process checks for all the dead objects and assigns them as the valid candidate for deletion to free up memory and promotes all the remaining objects in Gen-0 to Gen-1. So in the future when ever you clean up Gen-1 you have to clean up Gen-0 as well. When you fill up Gen – 0 again, all of Gen – 1 dead objects are drenched and rest are moved to Gen-2 and Gen-0 objects are moved to Gen-1 to free up Gen-0, but by this time your Garbage collection process has started to take much more time than it usually takes. Now as I mentioned earlier when garbage collection is being run all page requests that come in during that period are queued up. Does this explain why possibly page requests are getting queued up, apart from this it could also be the case that you are waiting for a long running database process to complete.      Lets explore the heap a bit more… What is really a case of crisis is when the objects are living long enough to make it to Gen-2 and then dying, this is definitely a high cost operation. But sometimes you need objects in memory, for example when you cache data you hold on to the objects because you need to use them right across the user session, which is acceptable. But if you wanted to see what extreme caching can do to your server then write a simple application that chucks in a lot of data in cache, run a load test over it for about 10-15 minutes, forcing a lot of data in memory causing the heap to run out of memory. If you get to such a state where you start running out of memory the IIS as a mode of recovery restarts the worker process. It is great way to free up all your memory in the heap but this would clear the cache. The problem with this is if the customer had 10 items in their shopping basket and that data was stored in the application cache, the user basket will now be empty forcing them either to get frustrated and go to a competitor website or if the customer is really patient, give it another try! How can you address this, well two ways of addressing this; 1. Workaround – A x86 bit processor only allows a maximum of 4GB of RAM, this means the machine effectively has around 3.4 GB of RAM available, the OS needs about 1.5 GB of RAM to run efficiently, the IIS and .net framework also need their share of memory, leaving you a heap of around 800 MB to play with. Because Team builds by default build your application in ‘Compile as any mode’ it means the application is build such that it will run in x86 bit mode if run on a x86 bit processor and run in a x64 bit mode if run on a x64 but processor. The problem with this is not all applications are really x64 bit compatible specially if you are using com objects or external libraries. So, as a quick win if you compiled your application in x86 bit mode by changing the compile as any selection to compile as x86 in the team build, you will be able to run your application on a x64 bit machine in x86 bit mode (WOW – By running Windows on Windows) and what that means is, you could use 8GB+ worth of RAM, if you take away everything else your application will roughly get a heap size of at least 4 GB to play with, which is immense. If you need a heap size of more than 4 GB you have either build a software for NASA or there is something fundamentally wrong in your application. 2. Solution – Now that you have put a workaround in place the IIS will not restart the worker process that regularly, which means you can take a breather and start working to get to the root cause of this memory leak. But this begs a question “How do I Identify possible memory leaks in my application?” Well i won’t say that there is one single tool that can tell you where the memory leak is, but trust me, ‘Performance Profiling’ is a great start point, it definitely gets you started in the right direction, let’s have a look at how. Performance Wizard - Start the Performance Wizard and select Instrumentation, this lets you measure function call counts and timings. Before running the performance session right click the performance session settings and chose properties from the context menu to bring up the Performance session properties page and as shown in the screen shot below, check the check boxes in the group ‘.NET memory profiling collection’ namely ‘Collect .NET object allocation information’ and ‘Also collect the .NET Object lifetime information’.    Now if you fire off the profiling session on your pages you will notice that the results allows you to view ‘Object Lifetime’ which shows you the number of objects that made it to Gen-0, Gen-1, Gen-2, Large heap, etc. Another great feature about the profile is that if your application has > 5% cases where objects die right after making to the Gen-2 storage a threshold alert is generated to alert you. Since you have the option to also view the most expensive methods and by capturing the IntelliTrace data you can drill in to narrow down to the line of code that is the root cause of the problem. Well now that we have seen how crucial memory management is and how easy Visual Studio Ultimate 2010 makes it for us to identify and reproduce the problem with the best of breed tools in the product. Caching One of the main ways to improve performance is Caching. Which basically means you tell the web server that instead of going to the database for each request you keep the data in the webserver and when the user asks for it you serve it from the webserver itself. BUT that can have consequences! Let’s look at some code, trust me caching code is not very intuitive, I define a cache key for almost all searches made through the common search page and cache the results. The approach works fine, first time i get the data from the database and second time data is served from the cache, significant performance improvement, EXCEPT when two users try to do the same operation and run into each other. But it is easy to handle this by adding the lock as you can see in the snippet below. So, as long as a user comes in and finds that the cache is empty, the user locks and starts to get the cache no more concurrency issues. But lets say you are processing 10 requests per second, by the time i have locked the operation to get the results from the database, 9 other users came in and found that the cache key is null so after i have come out and populated the cache they will still go in to get the results again. The application will still be faster because the next set of 10 users and so on would continue to get data from the cache. BUT if we added another null check after locking to build the cache and before actual call to the db then the 9 users who follow me would not make the extra trip to the database at all and that would really increase the performance, but didn’t i say that the code won’t be very intuitive, may be you should leave a comment you don’t want another developer to come in and think what a fresher why is he checking for the cache key null twice !!! The downside of caching is, you are storing the data outside of the database and the data could be wrong because the updates applied to the database would make the data cached at the web server out of sync. So, how do you invalidate the cache? Well if you only had one way of updating the data lets say only one entry point to the data update you can write some logic to say that every time new data is entered set the cache object to null. But this approach will not work as soon as you have several ways of feeding data to the system or your system is scaled out across a farm of web servers. The perfect solution to this is Micro Caching which means you cache the query for a set time duration and invalidate the cache after that set duration. The advantage is every time the user queries for that data with in the time span for which you have cached the results there are no calls made to the database and the data is served right from the server which makes the response immensely quick. Now figuring out the appropriate time span for which you micro cache the query results really depends on the application. Lets say your website gets 10 requests per second, if you retain the cache results for even 1 minute you will have immense performance gains. You would reduce 90% hits to the database for searching. Ever wondered why when you go to e-bookers.com or xpedia.com or yatra.com to book a flight and you click on the book button because the fare seems too exciting and you get an error message telling you that the fare is not valid any more. Yes, exactly => That is a cache failure! These travel sites or price compare engines are not going to hit the database every time you hit the compare button instead the results will be served from the cache, because the query results are micro cached, its a perfect trade-off, by micro caching the results the site gains 100% performance benefits but every once in a while annoys a customer because the fare has expired. But the trade off works in the favour of these sites as they are still able to process up to 30+ page requests per second which means cater to the site traffic by may be losing 1 customer every once in a while to a competitor who is also using a similar caching technique what are the odds that the user will not come back to their site sooner or later? Recap   Resources Below are some Key resource you might like to review. I would highly recommend the documentation, walkthroughs and videos available on MSDN. You can always make use of Fiddler to debug Web Performance Tests. Some community test extensions and plug ins available on Codeplex might also be of interest to you. The Road Ahead Thank you for taking the time out and reading this blog post, you may also want to read Part I and Part II if you haven’t so far. If you enjoyed the post, remember to subscribe to http://feeds.feedburner.com/TarunArora. Questions/Feedback/Suggestions, etc please leave a comment. Next ‘Load Testing in the cloud’, I’ll be working on exploring the possibilities of running Test controller/Agents in the Cloud. See you on the other side! Thank You!   Share this post : CodeProject

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  • Prepping a conference

    - by Laurent Bugnion
    I have had the chance to talk at many conferences these past few years, and came up with a way to prepare them which works really well for me. Most importantly, it would make it quite easy to overcome an emergency (for example if my laptop would suddenly lose data). The whole code as well as the slides and other documents are in the cloud. I also use source control for my demos, so that I always have the latest and the greatest, but also a history of changes I made to my demos. Finally I have a system of code snippets which works great, and I often had very positive remarks from the audience regarding that. Putting everything in the cloud The one thing I used to be the most scared of was a sudden crash of my laptop, and being unable to restore in time for a conference. Most conferences ask speakers to send slides a few days (or weeks…) in advance, but let's face it, we all have last minute changes to our talks and I always come in the conference with updated slides that I pass to the management team. The answer to that dilemma used to be working off memory sticks, and that worked not bad. However last year I started putting all the documents relating to a conference in a DropBox folder, and that works great too. Obviously DropBox works only if you have connectivity, so if I for instance update slides while on an international flight, I cannot save to the cloud. The obvious answer to that is to backup everything on a memory stick… but I have to admit, I have been trusting my luck and working off my laptop HD and then synching everything to the cloud after landing. Of course on some US national flights you get WiFi on board, so in that case it is even simpler :) Usually after the conference is done, I remove the files from DropBox and copy them to their "final destination". They are backed up from there to BackBlaze, the great online backup service I am using routinely (I currently have about 90GB of data in BackBlaze). Outlining the presentations I like to have a written outline of my presentations written somewhere. I keep it simple, just write the various sections of the presentation with timing. I guess it is a remnant of the time when I was a private pilot, and using checklists for flight preparation. For example: Demo about designability 15' (0:37) Switch to Blend Open MainPage.xaml Create a DataTemplate ... Here I can immediately see during the presentation if I am taking too much time for my demo (0:37 is where I need to be when I am done with this section of the presentation, and 15' is the time that this particular section takes). I keep these sections reasonable, I don't detail every step of the preparation. Typically I have one such section for every 10-15 minutes of my talks. Yes, I am timing my presentations. I keep adjusting these numbers when I rehearse, and this really helps to feel more confident during the presentations. This is especially important for presentations that are long, like my MIX11 demo which clocked at 57 minutes (I had a lot of stuff to show…). Such presentations are risky, because if anything goes wrong, you will have to cut stuff, so the answer to that is: Rehearse, rehearse and when you're done rehearsing, rehearse a little more. I also have a "Preparation" section where I outline what I need to do before a presentation. For instance: Preparation Reboot in VHD Make sure MSN and Twitter are not running. Open VS10 and load demo Open Blend and load demo Run the WP7 emulator ... I typically start preparing my laptop an hour before the talk, starting everything I need to start and then putting my laptop to sleep. Saving and printing the outline, Timing Printing is a real problem because it is really hard to find a printer at most conference venues, and also quite hard in hotels. To solve that, I simply write everything in OneNote (synched to the cloud, now you start to know what I like ;) and then I print it to a PDF (I use CutePDFWriter) that I save to my Kindle. During the presentation, I read the outline off the Kindle (I mostly just need a quick check to see how I am timing). For timing during the presentation, I use the free tool ChronoGPS on my Windows Phone 7, but of course any phone these days has a clock/chrono application. In some conferences, they even have timers that the presenters can see, but they tend to count down and I prefer to count up… so I just use my own :) Source control for demos For demos, I create a separate folder and use Mercurial as source control. Mercurial has the huge advantage (over SVN or TFS) to work offline too, so I can commit while on a plane, and all the history is saved. Then when I have connectivity I push everything to the cloud (I am using the fantastic Trunksapp.com for my private repositories). Here too the obvious downside is the risk of losing my last changes if my laptop crashes before I can push to the cloud, and here too the obvious answer would be to work from a memory stick… though I have to admit I didn't do that lately (except when I was writing Silverlight 4 Unleashed, where I was really paranoid…) And code snippets? I am one of these presenters who hates to type in front of an audience. I can type really fast (writing two books has this advantage, it really teaches you to touch type and be fast at it) but in the context of an audience, on a stage where it is often damn cold (an issue I had a lot in past conferences, air conditioning can freeze your fingers and make it really hard to type), it doesn't work as well. I don't know for you, but I really dislike seeing a presentation where the speaker uses the backspace key more often than others ;) To solve that, I like to have my code ready in snippets, and drag them to the screen. Then I can spend time explaining each code snippet, while highlighting portions of the code (always highlight what you talk about, the audience often doesn't even see the cursor and doesn't know where you are on the screen!) Over the years I have used various solutions for code snippets, and now I have one which works really well… if you take a few precautions! I use the Visual Studio Toolbox. Preparing the code snippets You can store code snippets in the Toolbox for anything, XAML, C# etc. I arrange the snippets in the order in which I need them, which is a great way to remember what comes next in the presentation. I also separate them by topic, to make it easier to find them, for example when I switch to the slides and then back to the code. Remember that no matter how experienced you are, you will feel more nervous on stage than while you are preparing, so any way to make it easier for you is going to be beneficial to the audience. To store a code snippet, I do the following: Open the final demo that you want to show to the audience in Visual Studio. In your code, select a snippet of code that you want to explain in particular. Make sure that the Visual Studio Toolbox is open (menu View, Toolbox or Ctrl-Alt-X). Drag the selected snippet from the code window to the toolbox. (if needed) drag the snippet to the correct location (for example between two other code snippets so that you can access it as you speak through the demo). Right click on the snippet and select Rename Item from the context menu. Select a meaningful name. For me I use the following conventions: If it is a method, I use the method's name. If it is not a whole method, I use a descriptive name. If it is the content of a method (i.e. the body only, without the method's signature), I use "-> MethodName". This reminds me during the presentation that this is only the body, and that I need to insert that into an existing signature. This is the case, for instance, when I use Visual Studio to automatically generate the members of an interface’s implementation; then I only need to insert my snippet inside the generated method body. Saving the snippets This is the most important!! It happened to me a few times that VS10 lost its settings. When that happens, the snippets are lost too! Yeah that really sucks, especially (as it happened once) when this is the case about an hour before a talk… Stress and sweat follows, not good conditions to start a talk in front of an audience believe me. Thankfully, saving snippets is really easy with the following steps: Select the menu Tools, Import and Export Settings. Select Export selected environment settings and press Next. Uncheck All Settings. Then expand General Settings and select Toolbox (only!). Press Next. Select your source control folder and save under a meaningful name (for instance Snippets.vssettings). Commit to source control and push to the cloud. By the way, this also has the advantage of applying source control to the snippets file (which is an XML file), so you get history for free on that file! Reimporting the snippets If VS loses its settings and you need to reimport the snippets, this can be done super easily and very fast. Make sure that the Toolbox is empty. When you import snippets, they are merged with existing ones, they do not replace the content of the Toolbox. Unless merging is really what you want, make sure that your Toolbox is clean before you import, it is really easier. Select the menu Tools, Import and Export Settings. Select Import selected environment settings and press Next. Select No, just import new settings and press Next. Press Browse and select the Snippets.vssettings file. Press Finish. Et voila, all your snippets appear again in the Toolbox. Whew, the worst was averted and you can start your demo without sweating! (I had to do that once literally 5 minutes before the start of a demo, while my laptop was already hooked to the projector, and it went just fine). What about special tools? When using special tools (for example beta versions of tools you have an early access to), or a special configuration of your laptop, things can get tricky because you cannot really be sure that you will get a laptop with the same tools and the same configuration at the conference. To solve that, I use the following precautions: I make my demos from a Virtual Hard Disk. The great John Papa made a very easy-to-follow web page where he explains how to create a VHD and install Win7 to it. This gives you the full power of your laptop (as fast as booting from the metal). For me, I have a basic configuration that I saved on a USB harddrive (Win7 plus drivers, basic settings for desktop, folder options, taskbar etc) and Visual Studio 2010 SP1 on it. When preparing, I start by copying this "basis VHD" to my laptop. I install additional tools and configurations. I save the VHD back to the USB harddrive in a different folder. This would allow me to reinstall my demo environment quite fast, for example in case of harddrive failure. Replace the harddrive, copy the VHD to it, configure the BCD and you can start. Unfortunately this only works if the laptop itself still works. In the worst case of total failure, my security is to back all the installers up: The installers I use are synched on all my laptops and backed up to BackBlaze. If the worst happens and my laptop is absolutely broken, I can download the installer from BackBlaze and install on another laptop. This of course takes some time, and if that happens 5 minutes before a presentation, well… I don't have an answer to that, except of course crossing my fingers. Still, all that gives me additional security. Conclusion Remember folks, talking to an audience, large or small, will make you nervous. Just ask Scott Hanselman :) The goal here is to create the best possible conditions for you, and to create an environment where everything is saved and easy to restore, where everything is well known and provides you with additional confidence. The cooler you feel before the presentation (and during ;)), the better your presentation will be. Here too, the goal is to provide the best user experience you can have, which in turn will make it more enjoyable for your audience! Happy presenting :) Laurent   Laurent Bugnion (GalaSoft) Subscribe | Twitter | Facebook | Flickr | LinkedIn

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  • Why does tracerpt use up all of my Sql Server's memory?

    - by Cypher
    We have a MS Sql Server 2008 machine with 12 GB of RAM... twice now within the last week this server was knocked on its backside by a process called "tracerpt.exe" which was found to have taken up ALL of the system's memory and leaving nothing for sqlserver. Done my homework, figured out what this program is... but still no idea why it's hogging up so much RAM (though I have an idea), nor what application is actually executing it. This server is the back-end to a Microsoft Dynamics CRM 4.0 application which is hosted on a separate server and is our production database used for just about everything. If this program is necessary, I would like to be able to find the application that is executing this thing and remove it or disable whatever feature is causing this quite annoying occurrence. Any ideas?

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  • Website with large number of users keeps going down due to memory leaks:Tomcat6 and Java 6

    - by user1766478
    We host many websites on one of our two virtual servers. We use tomcat 6 and Java 6. It is an MVC model with a hibernate like layer. The problem is, one of our biggest clients with the most number of members, keeps crashing the server every 6-8 hours(precisely in the mornings when most members login) We have been having this issue for 4 days now. Trying to figure out the problem but we suspect memory leaks. Any suggestions?

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  • Need data on disk drive management by OS: getting base I/O unit size, "sync" option, Direct Memory A

    - by Richard T
    Hello All, I want to ensure I have done all I can to configure a system's disks for serious database use. The three areas I know of (any others?) to be concerned about are: I/O size: the database engine and disk's native size should either match, or the database's native I/O size should be a multiple of the disk's native I/O size. Disks that are capable of Direct Memory Access (eg. IDE) should be configured for it. When a disk says it has written data persistently, it must be so! No keeping it in cache and lying about it. I have been looking for information on how to ensure these are so for CENTOS and Ubuntu, but can't seem to find anything at all! I want to be able to check these things and change them if needed. Any and all input appreciated.

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  • How to automatically show USB camera or memory stick contents in Icewm?

    - by darenw
    I normally use a very lightweight Linux setup. No desktop like Gnome or KDE, just Icewm as the windows manager and nothing else that normal users might consider essential. Well, I do need a file manager - I use Thunar. Recently I've been trying Gnome. Whenever I shove a memory stick into a USB port, or connect my digital camera, it can automatically pop up a file manager showing all the goodies on that device. KDE does this too. I like this. Although quick at the command line, I like not having to go sudo to mount the device and all that. If I want to stick with a lightweight setup using Icewm+Thunar, is there something non-huge I can install to make external devices fire up a Thunar window, or otherwise make access to the contents brainlessly easy?

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  • Word 2007 "Out of Memory or Disk Space" Error on launch.

    - by Adam
    Word 2007 is installed on a Vista Home Premium machine and whenever it starts up it opens what appears to be a dynamic installer to do something and then throws up the "Out of Memory or Disk Space" error. Word 2007 never completes starting up. Reinstalling Word hasn't helped and if I can avoid reinstalling Windows until Windows 7 is released and get Word working in the mean time, that would be ideal. I've been looking around for a solution, once of which seemed to point to a problem with the user account. I created a second user on the machine and Word still had the same problem. The other solution that seems possible is a corrupted normal.dot/normal.dotm file. However, even in the location it should be, I can't seem to find it. Am I going in the right direction with this? Is there another solution I haven't come across that will fix this? If it is possible that renaming normal.dot/normal.dotm how can I find it?

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