Planet MySQL Planet MySQL: Meta Deutsch Español Français Italiano 日本語 Русский Português 中文
10 Newer Entries Showing entries 31 to 40 of 704 10 Older Entries

Displaying posts with tag: Replication (reset)

Announcing orchestrator-agent
+0 Vote Up -0Vote Down

orchestrator-agent is a side-kick, complementary project of orchestrator, implementing a daemon service on one's MySQL hosts which communicates with and accepts commands from orchestrator, built with the original purpose of providing an automated solution for provisioning new or corrupted slaves.

It was built by Outbrain, with Outbrain's specific use case in mind. While we release it as open source, only a …

  [Read more...]
Exorcising the CAP Demon
+0 Vote Up -0Vote Down

Computer science is like an enormous tool box you can rummage through whenever you have a problem to solve. Most of the tools are sturdy and practical, like algorithms for B-trees. Some are also elegant, like consistent hashing in Dynamo. Finally there are some tools that you never quite figure out even after years of reflection. That piece of steel you are looking at could be Excalibur. Or it could be a rusty knife.

The CAP theorem falls into the last category, at least for me.  It was a major topic in the blogosphere a few years ago and Google Trends shows …

  [Read more...]
Replication from Oracle to MariaDB the simple way - Part 4
+0 Vote Up -0Vote Down

Now it's time to get serious about replicating to MariaDB from Oracle, and we are real close now, right? What I needed was a means of keeping track of what happens in a transaction, such as a LOG table of some kind, and then an idea of applying this log to MariaDB when there is a COMMIT in Oracle. And thing is, these two don't have to be related. So I can have a table which I write to and also have a Materialized View that is refreshed on COMMIT on, and I need a log table or something. And when the Materialized View is refreshed, as there is a COMMIT, then the log can be applied. From a schematic point-of-view, it looks something like this: …

  [Read more...]
WAIT_FOR_EXECUTED_GTID_SET for MySQL Replication
Employee_Team +1 Vote Up -0Vote Down

With the introduction of Global Transaction Identifiers(GTID) in MySQL from mysql-5.6 GA a whole lot of different functionality have been developed around it so that GTID could be used in a much simpler and efficient way.

One of the interesting functionality with GTID in use is the function to sync a slave with its
master server using the WAIT_UNTIL_SQL_THREAD_AFTER_GTIDS. This is used to do a timed or an indefinite wait till the servers in contention are in sync with respect to the GTID executed set.

This function is used to address specific use cases in which transactions are applied using SQL/worker thread. In order to …


  [Read more...]
Preserve Master’s Commit Order on Slave
Employee_Team +0 Vote Up -0Vote Down

On MySQL-5.7.2, we released a new type of multi-threaded slave (MTS). It is called logical clock based MTS. Because it can parallel apply transactions in the same schema, it has the potential to improve slave throughput on almost any application, regardless of the schema layout. After it was released, we continued to work on the framework to improve it further. Therefore, 5.7.5 includes a few enhancements, in addition to those released as part of previous DMRs. This blog post introduces one of the new features in the latest DMR.

slave_preserve_commit_order

It is a system global variable and can be set dynamically.

  • SET GLOBAL …
  [Read more...]
Transaction Retry Is Available On Multi-Threaded Slave
Employee_Team +0 Vote Up -0Vote Down

 I am happy to announce that slave_transaction_retries is available on multi-threaded slave now. You will no longer see the warning that slave_transaction_retries is not supported by multi-threaded slave since MySQL-5.7.5.

Multi-threaded slave and single-threaded slave share the system variable slave_transaction_retries and they have similar transaction retry logic. So this blog just brings you a little new knowledge and then refresh you with the transaction retry logic.

Transaction Retry In Worker Threads

For multi-threaded slave, Transaction retry is done in worker threads when they are applying their …

  [Read more...]
Replication from Oracle to MariaDB the simple way - Part 3
+0 Vote Up -0Vote Down

In this third installment in this series, I'll explain why the smart solution I described in the previous post actually wasn't that good, and then I go on to explain how to fix it, and why that fix wasn't such a smart thing after all. So, this was the design we ended with last time:
We have Oracle replicating to a Materialized View, this to ensure that we can run triggers when the is a commit, …

  [Read more...]
Replication from Oracle to MariaDB the simple way - Part 2
+0 Vote Up -0Vote Down

The theme for this series of posts is, and indicated in the previous post, "Try and try, again", and there will be more of this now when I start to make this work by playing with Oracle, with PL/SQL and with the restrictions of Oracle Express (which is the version I have available).

So, what we have right now is a way of "sending" SQL statements from Oracle to MariaDB, the question is when and how to send them from Oracle. The idea for this was then to use triggers on the Oracle tables to send the data to …

  [Read more...]
New MySQL Utility to Relocate Binary Logs
+0 Vote Up -0Vote Down

We are very happy to introduce a new MySQL utility named 'mysqlbinlogmove', which is used to relocate binary log files. This utility is one of two new utilities included in MySQL Utilities release-1.6.0 Alpha. The other utility is 'mysqlgrants', which is used to display the privileges (grants) of database objects.

Note: I use "binary log" to refer to both "kinds" of binary log files (binlog and relay log files) in general, and use "binlog" to refer specifically to those that are not "relay log" files.

The mysqlbinlogmove utility allows you to move binary log files to a new location taking care of correctly updating …



  [Read more...]
New MySQL Utility to Relocate Binary Logs
Employee_Team +0 Vote Up -0Vote Down

We are very happy to introduce a new MySQL utility named “mysqlbinlogmove“, which is used to relocate binary log files. This utility is one of two new utilities included in MySQL Utilities release-1.6.0 Alpha. The other utility is “mysqlgrants“, which is used to display the privileges (grants) of database objects.

Note: I use “binary log” to refer to both “kinds” of binary log files (binlog and relay log files) in general, and use “binlog” to refer specifically to those that are not “relay log” files.

The mysqlbinlogmove utility allows you to move binary log files to a new location taking …

  [Read more...]
10 Newer Entries Showing entries 31 to 40 of 704 10 Older Entries

Planet MySQL © 1995, 2015, Oracle Corporation and/or its affiliates   Legal Policies | Your Privacy Rights | Terms of Use

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.