The Question Recently, a customer asked us:

If we move to using the INI configuration method instead of staging, would password-less SSH still be required?

The Answer The answer is both “Yes” and “No”

No, for installation and updates/upgrades specifically. Since INI-based configurations force the tpm command to act upon the local host only for installs and updates/upgrades, password-less SSH is not required.

Yes, because there are certain commands that do rely upon password-less SSH to function. These are:

• tungsten_provision_slave
• prov-sl.sh
• multi_trepctl
• tpm diag (pre-6.0.5)
• tpm diag --hosts (>= 6.0.5)
• Any tpm-based backup and restore operations that involve a remote node

Summary The Wrap-Up

In …

Overview The Skinny

In this blog post we will discuss how to best integrate various Continuent-bundled cluster monitoring solutions with PagerDuty (pagerduty.com), a popular alerting service.

Agenda What’s Here?

• Briefly explore the bundled cluster monitoring tools
• Describe the procedure for establishing alerting via PagerDuty
• Examine some of the multiple monitoring tools included with the Continuent Tungsten Clustering software, and provide examples of how to send an email to PagerDuty from each of the tools.

Exploring the Bundled Cluster Monitoring Tools A Brief Summary

Continuent provides multiple methods out of the box to monitor the cluster health. The most popular is the suite of Nagios/NRPE scripts (i.e. cluster-home/bin/check_tungsten_*). We also have Zabbix scripts (i.e. cluster-home/bin/zabbix_tungsten_*). Additionally, there is …

Wondering which databases are trending in 2019? We asked hundreds of developers, engineers, software architects, dev teams, and IT leaders at DeveloperWeek to discover the current NoSQL vs. SQL usage, most popular databases, important metrics to track, and their most time-consuming database management tasks. Get the latest insights on MySQL, MongoDB, PostgreSQL, Redis, and many others to see which database management systems are most favored this year.

SQL vs. NoSQL

As any database administrator knows, the first question you have to ask yourself is whether to use a SQL or NoSQL database for your application. …

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MySQL changed the timestamp format in the log files in MySQL 5.7. Since then, I have a few times seen questions about the new format, and how to change the time zone that is used. Latest in a comment to my blog about log_slow_extra in 8.0.14, where the question was what T and Z in the timestamp (for example 2019-01-31T07:24:06.100447Z) means. In this blog, I will discuss the timestamp format and show you how you can change the time zone used.

Examples of the timestamps from the MySQL error log when restarting MySQL (click to enlarge).
The MySQL 5.7 Change

In MySQL 5.7 it was decided to make two …

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The slow query log is the trusted old method of recording slow query, so the database administrator can determine which queries are in the most need for optimization. Since MySQL 5.6, it has to some extend been overshadowed by the Performance Schema which has lower overhead and thus allows collecting statistics about all queries. The slow query log has one major advantage though: the data is persisted. In MySQL 8.0.14 which was recently released, there is an improvement for the slow query log: additional statistics about the recorded queries.

The slow query log with log_slow_extra enabled.

Contribution

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In a MySQL hosting replication setup, the parameter Seconds_Behind_Master (SBM), as displayed by the SHOW SLAVE STATUS command, is commonly used as an indication of the current replication lag of the slave. In this blog post, we examine how to understand and interpret this value in various situations.

Possible Values of  Seconds Behind Master

The value of SBM, as explained in the  MySQL documentation, depends on the state of the MySQL slave in general, and the states of MySQL slave SQL_THREAD and IO_THREAD in particular. While IO_THREAD connects with the master and reads the updates, SQL_THREAD applies these updates on the slave. Let’s examine the possible values of SBM during different states of the MySQL Slave.

When SBM Value is Null

• SBM is …

I am a Junior DBA at Mydbops. This is my first blog professionally, I would like to brief my encounter with Log-rotate in first few weeks of my work,  Hope it will help other beginners as well. This Blog will cover the following sections.

• Introduction to Log-rotate

• Issues Faced

• Solutions (Fix for the above issues)

• Best practices

  • How to configure the Log-rotate

  • Operation of Log-rotate

  • Files responsible for the Log_rotate utility.

1.0. Introduction to Log-rotate:

• Log-rotate is a utility and …

Have you been experiencing slow MySQL startup times in GTID mode? We recently ran into this issue on one of our MySQL hosting deployments and set out to solve the problem. In this blog, we break down the issue that could be slowing down your MySQL restart times, how to debug for your deployment, and what you can do to decrease your start time and improve your understanding of GTID-based replication.

How We Found The Problem

We were investigating slow MySQL startup times on a low-end, disk-based MySQL 5.7.21 deployment which had GTID mode enabled. The system was part of a master-slave pair and was under a moderate write load. When restarting during a scheduled maintenance, we …

MySQL 8.0.13 improves replication lag monitoring by extending the instrumentation for transaction transient errors. These temporary errors, which include lock timeouts caused by client transactions executing concurrently as the slave is replicating, do not stop the applier thread: instead, they cause a transaction to retry.…

One important way to protect your data is to keep your Tungsten Clustering software up-to-date.

A standard cluster deployment uses three nodes, which allows for no-downtime upgrades along with the ability to have a fully available cluster during maintenance.

Please note that with only two database cluster nodes, there is a window of vulnerability created by leaving zero failover candidates available when the lone slave is taken down for service.

The Best Practices: Staging Performing a No-Downtime Upgrade for a Staging Deployment

When upgrading a Staging-style deployment, all nodes are upgraded at once in parallel via the tools/tpm update command run from inside the staging directory on the staging host.

No Master switch happens, and all layers are restarted to use the new code. …