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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 the respective index file for you. This utility can be very useful if you want to change the location to store the binlog file and you want to move all[Read more...]
In the first part of this article we examined the types of conflicts and their causes. In this part, we will analyse some of the methods available to deal with conflicts.
Applicability: synchronous clusters with 2pc
We've covered this topic in the previous article, but it's worth repeating. If you use a synchronous cluster, you don't have conflicts. For example, MySQL Cluster ensures consistent data with updates coming from different nodes. However, MySQL Cluster is not a replacement for a MySQL server, and it has severe limitations.
Applicability: synchronous clusters without 2pc (Galera)
Conflicting transactions proceed on different[Read more...]
Well... we actually have a few options to tweak it, but nothing required to turn it on. It even works for existing engines since we did not have to extend the handlerton interface to implement the binary log group commit. However, InnoDB has some optimizations to take advantage of the binary log group commit implementation.
When using the replication slave stream, or mysql command line client and mysqlbinlog output from a binary/relay log, all statements are executed in a single thread as quickly as possible.
I am seeking a tool to simulate the replay of the binary/relay log for a benchmark at a pace that is more representative to original statements. For a simple example, if the Binary Log has 3 transactions in the first second, 2 transactions in the second second, and 5 transactions in the third second, I am wanting to simulate the replay to take roughly 3 seconds, not as fast as possible (which would be sub-second). The tool should try to wait the remainder of a second before processing SQL statements in the incoming stream.
Does anybody know of a tool that currently provides this type of functionality? Any input appreciated before I create my own.
Even when the output of EXPLAIN doesn’t show “using temporary”, a temporary file may still be used in certain cases.
That’s not to say the query needs the temporary file to actually resolve the query (like what you’d see from the need for a derived table). But rather, the temporary file I’m speaking of is due to binary logging.
In particular, you can see this easily if using InnoDB, (most commonly) row-based binary logging, and you issue a large transaction, say a large
UPDATE (large meaning something larger than the size of
CREATE PROCEDUREstatement in such a way that, if I extract the query from the binary log and apply it to another server, the information is still available.
CREATE PROCEDURE p1(i int) select "hello" /* This is my text */
This is the second in a series on what's seriously limiting MySQL in certain circumstances (links: part 1). In the first part, I wrote about single-threaded replication. Upstream from the replicas is the primary, which enables replication by writing a so-called "binary log" of events that modify data in the server. The binary log is a real limitation in MySQL.
The binary log is necessary not only for replication, but for point-in-time recovery, too. Given a backup and the corresponding binary log position, you can replay the binary log and roll forward the state of your server to a desired point in time.
But enabling the binary log reduces MySQL's performance dramatically. It is not the logging itself that's the problem -- writing[Read more...]
Scenario: Master-Master replication
Description: Master A is the active db server whilst Master B is a read only swappable db server hence both are creating binary logs. During backup I run “FLUSH LOGS” in order to have a simpler point in time recovery procedure if that case arises.
Problem: Flush logs is mean mean command :) …. it rotates not only my binary logs but my error log too (since I user error-log=blahblahblah in my my.cnf). Well given I flush logs every night my error log is cycled through every night, but unlike binary logs which have an incrimental number attached to the fine, error logs only have a `-log` attached to the filename and a second “FLUSH LOG” would just clear all error logs permanently. That is really not fun believe me!
So what is the solution?[Read more...]
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