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Displaying posts with tag: configuration (reset)
Enforce Primary Key constraints on Replication

In this post, we introduce a configuration option that controls whether replication channels allow the creation of tables without primary keys. This continues our recent work on replication security, where we allowed users to enforce privilege checks, and/or enforce row-based events.…

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Replication with restricted privileges

Up until MySQL 8.0.18, the slave executes replicated transactions without checking privileges. It does so to be able to apply everything that its upstream server (the master) tells it to. In practice this means that the slave fully trusts its master.…

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Enabling Autorecovery for the Tungsten Replicator

The Replicator is a critical piece of the Tungsten Clustering solution for MySQL / MariaDB, as well as its own stand-alone data replication product. Automatic recovery is a feature that enables the Replicator to go back online in the event of a transient failure. In this blog we discuss how to enable Automatic Recovery. For more information about Auto-Recovery, please click here to visit the online documentation page.

The Question Recently, a customer asked us:

We see that the replicators receive a transaction which has a deadlock error in it:

pendingError : Event application failed: seqno=82880882 fragno=0 message=java.sql.SQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction

If one performs a service online, it comes back online without issue and continues …

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What is the Best Way to Check the Health of a Tungsten Cluster Before a Switch?

The Question Recently, a customer asked us:

What would cause a node switch to fail in a Tungsten Cluster?

For example, we saw the following during a recent session where a switch failed:

cctrl> switch to db3 

SELECTED SLAVE: db3@alpha 
Exception encountered during SWITCH. 
Failed while setting the replicator 'db1' role to 'slave' 
ClusterManagerException: Exception while executing command 'replicatorStatus' on manager 'db1' 
Exception=Failed to execute '/alpha/db1/manager/ClusterManagementHelper/replicatorStatus alpha db3' 
|alpha | …
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How to validate server configuration settings.

After upgrading the server many users start it with an unchanged config file only to find some deprecated options that they were using are no longer supported by the later server version, which causes the upgraded server to shutdown. In other cases modifying the server configuration file results in the server refusing to start when an invalid name is mistakenly entered in the configuration file.…

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Check the MySQL server startup configuration

Since 8.0.16, MySQL Server supports a --validate-config option that enables the startup configuration to be checked for problems without running the server in normal operational mode. --validate-config can be used any time, but is particularly useful after an upgrade, to check whether any options previously used with the older server are considered by the upgraded server to be deprecated or obsolete.

binlog-row-event-max-size system variable in MySQL 8.0.14

As you may have noticed by now, we are continuously improving and enhancing the experience of managing a MySQL server. Furthermore, we have also released tools, such as MySQL shell, that make advanced and distributed setups like creating, deploying, and running clusters of InnoDB instances, seamless to the end user.…

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Binary log encryption at rest

Starting in version 8.0.14, MySQL server can encrypt all new binary and relay log files on disk. In order to do so, you just need to enable the new binlog_encryption option (and also ensure that you have a keyring).…

How to Fix ProxySQL Configuration When it Won’t Start

With the exception of the three configuration variables described here, ProxySQL will only parse the configuration files the first time it is started, or if the proxysql.db file is missing for some other reason.

If we want to change any of this data we need to do so via ProxySQL’s admin interface and then save them to disk. That’s fine if ProxySQL is running, but what if it won’t start because of these values?

For example, perhaps we accidentally configured ProxySQL to run on port 3306 and restarted it, but there’s already a production MySQL instance running on this port. ProxySQL won’t start, so we can’t edit the value that way:

2018-10-02 09:18:33 network.cpp:53:listen_on_port(): [ERROR] bind(): Address already in use

We could delete proxysql.db and have it reload the configuration files, but …

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Scaling Percona Monitoring and Management (PMM)

Starting with PMM 1.13,  PMM uses Prometheus 2 for metrics storage, which tends to be heaviest resource consumer of CPU and RAM.  With Prometheus 2 Performance Improvements, PMM can scale to more than 1000 monitored nodes per instance in default configuration. In this blog post we will look into PMM scaling and capacity planning—how to estimate the resources required, and what drives resource consumption.

We have now tested PMM with up to 1000 nodes, using a virtualized system with 128GB of memory, 24 virtual cores, and SSD storage. We found PMM scales pretty linearly with the available memory and CPU cores, and we believe that a higher number of nodes could be …

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