Search Results

Search found 1054 results on 43 pages for 'replication'.

Page 7/43 | < Previous Page | 3 4 5 6 7 8 9 10 11 12 13 14  | Next Page >

  • Articles about replication schemes/algorithms?

    - by jkff
    I'm designing an hierarchical distributed system (every node has zero or more "master" nodes to which it propagates its current data). The data gets continuously updated and I'd like to guarantee that at least N nodes have almost-current data at any given time. I do not need complete consistency, only eventual consistency (t.i. for any time instant, the current snapshot of data should eventually appear on at least N nodes. It is tricky to define the term "current" here, but still). Nodes may fail and go back up at any moment, and there is no single "central" node. O overflowers! Point me to some good papers describing replication schemes. I've so far found one: Consistency Management in Optimistic Replication Algorithms

    Read the article

  • sql server 2005 replication article conflict

    - by Daniel
    Hi all, I have a sql server 2005 database that I want to setup replication for. The problem is that the database has two schemas both of which have a table with the same name in it. For some reason even though the tables are in different schemas the replication creation fails when done through management studio due to conflicting article names (i assume its trying to create the same name for both tables in the different schemas). Is there any workaround for doing this in the studio, I can probably write a script or program to do this but just for this one thign is a bit annoying and it probably wont be allowed to run in production. Perhaps there is a hot fix or something I'm not aware about? Cheers,

    Read the article

  • Small script to look for Project Replication actions that have failed

    - by Trond Strømme
    Today when looking at a couple of projects on a ZFS 7320 Storage Appliance I noticed on one project that one of its replication actions had failed, as I hadn't checked the Recent Alerts log yet I was not aware of this. I decided to write a small script to check if there were others that had failed. Nothing fancy, just a loop through all projects, look at the project's replication child and compare the values of the last_sync and last_try properties and print the result if they're not equal. (There are probably more sensible ways of doing this, but at least it involves me getting the chance to put on my headphones and doing just a little bit of coding.) script // this script will locate failed project level replication // it will look at the sync times for 'last_sync' and 'last_try' // and compare these, if they deviate you should investigate. // NOTE! this code is offered 'as is' Run at your own risk, // it will probably work as intended, but in now way can I // (or Oracle) be held responsible if your server starts behaving // like a three year old kid in a candy store.. (not that mine do, // they are very well behaved boys...) run('configuration'); run('storage'); printf('Host: %s, pool: %s\n', get('owner'),get('pool')); run('cd /'); run('shares'); proj=list(); printf("total projects: %d\n",proj.length +'\n'); // just for project level replication for(i=0;i<proj.length;i++){ run('select '+proj[i]); run('replication'); //get all replication actions preps = list(); for(j=0;j<preps.length;j++){ run('select ' + preps[j]); last_sync = get('last_sync'); last_try = get('last_try'); // printf("target %s\n", get('target')); //why the flip does this not get the proper name? if(!( last_sync.valueOf() === last_try.valueOf())){ printf("sync has failed for %s %s\n", proj[i], get('target')); }else{ // printf("OK %s %s\n", proj[i], get('target')); } run('done'); //done with the replica action } run('done'); run('done'); } printf("finished\n"); For a more on how to run the script, or testing it please look at my previous post. Sample output: Host: elb1sn01, pool: exalogic total projects: 45 sync has failed for ACSExalogicSystem cb3a24fe-ad60-c90f-d15d-adaafd595639 finished

    Read the article

  • MySQL replicate multiple places

    - by Frederik Nielsen
    Very trick task to find a good title for this question, but here goes the q: I have a few development machines, where I develop my PHP applications on, and testing via a local webserver. This works out pretty well for each machine. However, I would like to replicate the DB from my machines to a central location. So, to sum up: DEV1 - CENTRAL DEV2 - CENTRAL DEV3 - CENTRAL CENTRAL - DEV1 CENTRAL - DEV2 CENTRAL - DEV3 I hope this makes sense, as I cannot find an easy way to tell it. Basically, it is a 2-way replication, where all 4 databases contain the same info, and each of them can be updated locally, to then be pushed out to the others. Is this actually doable? All my dev machines are running Windows 7, and my central DB server is running CentOS 6.

    Read the article

  • FOSS ASP.Net Session Replication Solution?

    - by jsight
    I've been searching (with little success) for a free/opensource session clustering and replication solution for asp.net. I've run across the usual suspects (indexus sharedcache, memcached), however, each has some limitations. Indexus - Very immature, stubbed session interface implementation. Its otherwise a great caching solution, though. Memcached - Little replication/failover support without going to a db backend. Several SF.Net projects - All aborted in the early stages... nothing that appears to have any traction, and one which seems to have gone all commercial. Microsoft Velocity - Not OSS, but seems nice. Unfortunately, I didn't see where CTP1 supported failover, and there is no clear roadmap for this one. I fear that this one could fall off into the ether like many other MS dev projects. I am fairly used to the Java world where it is kind of taken for granted that many solutions to problems such as this will be available from the FOSS world. Are there any suitable alternatives available on the .Net world?

    Read the article

  • Sql Server Replication: Snapshot vs Merge

    - by Zyphrax
    Background information Let's say I have two database servers, both SQL Server 2008. One is in my LAN (ServerLocal), the other one is on a remote hosting environment (ServerRemote). I have created a database on ServerLocal and have an exact copy of that database on ServerRemote. The database on ServerRemote is part of a web application and I would like to keep it's data up-to-date with the data in the database ServerLocal. ServerLocal is able to communicate with ServerRemote, this is one-way traffic. Communication from ServerRemote to ServerLocal isn't available. Current solution I thought it would be a nice solution to use replication. So I've made ServerLocal a publisher and subscriptions are pushed to the ServerRemote. This works fine, when a snapshot is transfered to ServerRemote the existing data will be purged and the ServerRemote database is once again an exact replica of the database on ServerLocal. The problem Records that exist on ServerRemote that don't exist on ServerLocal are removed. This doesn't matter for most of my tables but in some of my tables I'd like to keep the existing data (aspnet_users for instance), and update the records if necessary. What kind of replication fits my problem?

    Read the article

  • How to synchronize two (or n) replication processes for SQL Server databases?

    - by Yauheni Sivukha
    There are two master databases and two read-only copies updated by standard transactional replication. It is needed to map some entity from both read-only databases, lets say that A databases contains orders and B databases contains lines. The problem is that replication to one database can lag behind replication of second database, and at the moment of mapping R-databases will have inconsistent data. For example. We stored 2 orders with lines at 19:00 and 19:03. Mapping process started at 19:05, but to the moment of mapping A database replication processed all changes up to 19:03, but B database replication processed only changes up to 19:00. After mapping we will have order entity with order as of 19:03 and lines as of 19:00. The troubles are guaranteed:) In my particular case both databases have temporal model, so it is possible to fetch data for every time slice, but the problem is to identify time of latest replication. Question: How to synchronize replication processes for several databases to avoid situation described above? Or, in other words, how to compare last time of replication in each database? UPD: The only way I see to synchronize is to continuously write timestamps into service tables in each database and to check these timestamps on replicated servers. Is that acceptable solution?

    Read the article

  • Database Replication

    - by tanthiamhuat
    I have tried to follow the steps outlined in http://www.howtoforge.com/mysql_database_replication for Database Replication. I have created the database exampledb, and create some tables and load them with values. But when I execute USE exampledb; FLUSH TABLES WITH READ LOCK; SHOW MASTER STATUS; I do not get any output, it says 0 rows affected. why is it so?

    Read the article

  • Mysql Replication

    - by ychian
    My current database design uses MyIsam mainly as the storage engine, I wonder if its possible to split some of the tables into MyIsam and some into Innodb in the same database. Reason of switching some of the tables to Innodb is because i need row-based locking which Innodb offers. I am not too sure whether this would have any effect on replication?

    Read the article

  • Website Replication using Wordpress

    - by chouputra
    Hi I have a wordpress installed on h*ttp://domainname.com and I would like to have replication of the same website on a subdomain for example h*ttp://sub1.domainname.com h*ttp://sub2.domainname.com What should I do to make this happen without copying any database and the wordpress should be smart enough to recognize the "sub1" and "sub2" to be used later in the program.

    Read the article

  • binlog_format = STATEMENT and CURRENT_TIMESTAMP with MySQL replication

    - by xma
    Hi, can a MySQL slave instance have different row values for the same ID when binlog_format is set to STATEMENT and we insert something like: insert into foo values(CURRENT_TIMESTAMP) As I understand it, the slave read the SQL statement and execute it thus, if the replication is lagging, could lead to differences for the same row. Right or wrong ? How can I avoid this situation ? Thank you.

    Read the article

  • What to consider if using triggers on tables in a sql-server merge replication

    - by Ice
    Hi, i am driving since some years a sql-server2000 merge-replication over three locations. Triggers do a lot of work in this database. i got no troubles. Now migrating these database to a brand new sql2008, i got some issues about the triggers. They are firing even if the merge-agent does his work. Is there anybody who has some experience with that kind of stuff on sql2008-server? Can anybody confirm that different behaviour to sql2000? Peace Ice

    Read the article

  • Replication - syncronizing most of the data some of the time

    - by uncle brad
    I have some data that isn't properly "partitioned" (for lack of a better word). All inserts, processing and reporting happen on the same table. The bulk of the processing happens not long after the insert and not long after that it becomes immutable (we're talking days). I could do all inserts and processing on a new table that I replicate to the old table. When I detect that the data has become immutable I would delete the data from the new table, but I would edit the delete replication stored procedure so that the delete did not replicate. How bad an idea is this? It seems attractive at the moment (I haven't slept on it yet) because it might mitigate a performance problem with only very small changes to the application. It also seems like it might be a good way to shoot myself in the foot.

    Read the article

  • Filtering coluns in SQL Server replication - how?

    - by truthseeker
    Hi, I need to replicate some data from two tables in one database to another databases. I used snapshot replication. The issue is that I would like to replicate only some selected columns and the others should stay with untouched data. I don't want to loose their data. The sours of those columns is other system. So I need to replicate only data from my columns. Do anybody know how to achieve this?

    Read the article

  • SQL Server Express 2005 Merge Replication using RMO causes Null Reference exception

    - by Craig Shearer
    I'm trying to use RMO to programmatically perform merge synchronization. I've basically copied the SQL Server example code, as follows: // Create a connection to the Subscriber. ServerConnection conn = new ServerConnection(subscriberName); MergePullSubscription subscription; try { // Connect to the Subscriber. conn.Connect(); // Define the pull subscription. subscription = new MergePullSubscription(subscriptionDbName, publisherName, publicationDbName, publicationName, conn, false); // If the pull subscription exists, then start the synchronization. if (subscription.LoadProperties()) { // Check that we have enough metadata to start the agent. if (subscription.PublisherSecurity != null || subscription.DistributorSecurity != null) { subscription.SynchronizationAgent.Synchronize(); } else { throw new ApplicationException("There is insufficent metadata to " + "synchronize the subscription. Recreate the subscription with " + "the agent job or supply the required agent properties at run time."); } } else { // Do something here if the pull subscription does not exist. throw new ApplicationException(String.Format( "A subscription to '{0}' does not exist on {1}", publicationName, subscriberName)); } } catch (Exception ex) { // Implement appropriate error handling here. throw new ApplicationException("The subscription could not be " + "synchronized. Verify that the subscription has " + "been defined correctly.", ex); } finally { conn.Disconnect(); } I've got the server merge publication defined correctly, but when I run the above code, I get a null reference exception on the call to: subscription.SynchronizationAgent.Synchronize(); The stack trace is as follows: at Microsoft.SqlServer.Replication.MergeSynchronizationAgent.StatusEventSinkMethod(String message, Int32 percent, Int32* returnValue) at Test.ConsoleTest.Program.SynchronizePullSubscription() in F:\Visual Studio Projects\Test\source\Test.ConsoleTest\Program.cs:line 124 It seems, from the stack trace, like something to do with the Status event, but I don't have a handler defined, and defining one makes no difference.

    Read the article

  • db4o Replication System: NullReferenceException?

    - by virtualmic
    Hi, I am trying to do standard bi-directional replication as follows. However, I get a NullReferenceException. This is a separate replication project. I did import the classes involved in the original project (such as Item, Category etc.) in this replication project. What am I doing wrong? (If I debug using VS, I can see that changedObjects does have all the changed objects; there seems to be some problem inside Replicate function) IObjectContainer local = Db4oFactory.OpenFile(@"G:\Work\School\MIS\VINMIS\Inventory\bin\Debug\vin.db4o"); IObjectContainer far = Db4oFactory.OpenFile(@"\\crs-lap\c$\vinmis\vin.db4o"); ; IReplicationSession replication = Replication.Begin(local, far); IObjectSet changedObjects = replication.ProviderA().ObjectsChangedSinceLastReplication(); while(changedObjects.HasNext()) replication.Replicate(changedObjects.Next()); // Exception!!! replication.Commit(); changedObjects = replication.ProviderB().ObjectsChangedSinceLastReplication(); while (changedObjects.HasNext()) replication.Replicate(changedObjects.Next()); replication.Commit(); Regards, Saurabh.

    Read the article

  • Merge replication server side foreign key violation from unpublished table

    - by Reiste
    We are using SQL Server 2005 Merge Replication with SQL CE 3.5 clients. We are using partitions with filtering for the separate subscriptions, and nHibernate for the ORM mapping. There is automatic ID range management from SQL Server for the subscriptions. We have a table, Item, and a table with a foreign key to Item - ItemHistory. Both of these are replicated down, filtered according to the subscription. Item has a column called UserId, and is filtered per subscription with this filter: WHERE UserId IN (SELECT... [complicated subselect]...) ItemHistory hangs off Item in the publication filter articles. On the server, we have a table ItemHistoryExport, which has a foreign key to ItemHistory. ItemHistoryExport is not published. Entries in the Item and ItemHistory tables are never deleted, on the server or the client. However, the "ownership" of items (and hence their ItemHistories) MAY change, which causes them to be moved from one client subscription/partition to another from time to time. When we sync, we occasionally get the following error: A row delete at '48269404 - 4108383dbb11' could not be propagated to 'MyServer\MyInstance.MyDatabase'. This failure can be caused by a constraint violation. The DELETE statement conflicted with the REFERENCE constraint "FK_ItemHistoryExport_ItemHistory". The conflict occurred in database "MyDatabase", table "dbo.ItemHistoryExport", column 'ItemHistoryId'. Can anyone help us understand why this happens? There shouldn't ever be a delete happening on the server side.

    Read the article

  • Problem while Installing mysql cluster

    - by Champion
    I downloaded latest mysql cluster file 64 bit (mysql-cluster-gpl-7.1.9-linux-x86_64-glibc23) from mysql site. Ran following command to install mysql server. /home/mysql_cluster/mysqlc/scripts/mysql_install_db --no-defaults --basedir=/home/mysql_cluster/mysqlc --datadir=/home/mysql_cluster/my_cluster/mysqld_data It's giving following issues. /home/mysql_cluster/mysqlc/scripts/mysql_install_db: line 245: /home/mysql_cluster/mysqlc/bin/my_print_defaults: No such file or directory Neither host 'db' nor 'localhost' could be looked up with /home/mysql_cluster/mysqlc/bin/resolveip Please configure the 'hostname' command to return a correct hostname. If you want to solve this at a later stage, restart this script with the --force option My host is pinging and hostname command gives correct hostname. I tried also with --force option force but still not working giving following issues: /home/mysql_cluster/mysqlc/scripts/mysql_install_db: line 245: /home/mysql_cluster/mysqlc/bin/my_print_defaults: No such file or directory Installing MySQL system tables... /home/mysql_cluster/mysqlc/scripts/mysql_install_db: line 393: /home/mysql_cluster/mysqlc/bin/mysqld: No such file or directory Installation of system tables failed! Examine the logs in /home/mysql_cluster/my_cluster/mysqld_data for more information. It says above files doesn't exist but this files are present checked with ls command. We are using XEN VM with 64 bit debian lenny os. How this issue can be resolved ?

    Read the article

  • mysql master slave "table already exists" but table not exists

    - by Korjavin Ivan
    I have 1 master mysql process, and 2 slave. Today on both slaves i see : Error 'Table 'bgbilling.contract_status_balance_dump' already exists' on query. Default database: 'bgbilling'. Query: 'CREATE TABLE contract_status_balance_dump( UNIQUE(cid) ) SELECT cid, MAX(yy*12+(mm-1))%12 + 1 AS mm,FLOOR(MAX(yy*12+(mm-1)) / 12) AS yy FROM contract_balance GROUP BY cid' "show tables" does not show this table. I tryed stop slave , and do "drop table contract_status_balance_dump" but: ERROR 1051 (42S02): Unknown table 'contract_status_balance_dump' How its possible? And how fix that?

    Read the article

  • Best Solution for Load Balancing geographically distributed NFS File Access?

    - by DairyKnight
    I'm trying to find an optimum solution for accessing the NFS file share in my company. We have a central file server in North America and has 30GB~50GB of updated data everyday. And it's very slow for our Europe and Asia branches to access directly. Therefore, I'm trying to setup two replicate servers in those continents. I'm currently using rsync, but wonder if there exists a better solution acts more like a distributed RAID, which allows the user to transparently access the file whether synced or not. And user request will be dispatched to remote server if the file is not yet synced. I'm now looking into DRBD, but it seems not to have the functionality of auto-dispatching requests. Does anyone know if there's a better solution?

    Read the article

  • MySQL simple replication problem: 'show master status' produces 'Empty set'?

    - by simon
    I've been setting up MySQL master replication (on Debian 6.0.1) following these instructions faithfully: http://www.neocodesoftware.com/replication/ I've got as far as: mysql > show master status; but this is unfortunately producing the following, rather than any useful output: Empty set (0.00 sec) The error log at /var/log/mysql.err is just an empty file, so that's not giving me any clues. Any ideas? This is what I have put in /etc/mysql/my.cnf on one server (amended appropriately for the other server): server-id = 1 replicate-same-server-id = 0 auto-increment-increment = 2 auto-increment-offset = 1 master-host = 10.0.0.3 master-user = <myusername> master-password = <mypass> master-connect-retry = 60 replicate-do-db = fruit log-bin = /var/log/mysql-replication.log binlog-do-db = fruit And I have set up users and can connect from MySQL on Server A to the database on Server B using the username/password/ipaddress above.

    Read the article

< Previous Page | 3 4 5 6 7 8 9 10 11 12 13 14  | Next Page >