The latest from the MySQL community

Earlier in the blog series, we touched upon deployment of clustering/replication (MySQL / Galera, MySQL Replication, MongoDB & PostgreSQL), management & monitoring of your existing databases and clusters, performance monitoring and health, how to make your setup highly available through HAProxy and MaxScale, how to prepare yourself for disasters by scheduling …

In previous blog, I covered DISK/IO counters. This blog will briefly touch on Network, Threading and Contention.

Other counters:
Network I/OCOUNTER: Network Interface\Bytes Total/sec
TYPE: Instantaneous
USAGE:

#Get Instances
PS > (New-Object Diagnostics.PerformanceCounterCategory("Network Interface")).GetInstanceNames("")

Intel[R] Centrino[R] Advanced-N 6205
Microsoft Virtual WiFi Miniport Adapter _2
Microsoft Virtual WiFi Miniport Adapter
Intel[R] 82579LM Gigabit Network Connection

PS > New-Object Diagnostics.PerformanceCounter("Network Interface",
"Bytes Total/sec", "Intel[R] 82579LM Gigabit Network Connection")

CategoryName …

You may sometimes hear complaints about MySQL not providing good enough tools for profiling and execution analysis. A few years ago I would have agreed with such opinions, thankfully MySQL developers have made huge efforts to improve the situation in recent major versions. MySQL DBAs now have some great native diagnostic tools at their disposal... which is totally not what this article is about :)
Native MySQL tooling (whatever it might be) is just the tip of the iceberg and if you want to be a better troubleshooter, SysAdmins are the first people you should talk to. Their toolboxes are full of awesomeness and the tools they use have one significant advantage over MySQL tools: they can analyze server execution holistically, regardless of the MySQL version you may be using.
In this article, we will have a look at three OS-level tools: pstack, perf and callgrind (Valgrind tool).

Introduction Tools …

With Unicode it is possible for strings to look the same, but with slight differences in which codepoints are used.

For example the é in Café can be <U+0065 U+0301> or <U+00E9>.

The solution is to use Unicode normalization, which is supported in every major programming language. Both versions of Café will be normalized to use U+00E9.

In the best situation the application inserting data into the database will do the normalization, but that often not the case.

This gives the following issue: If you search for Café in the normalized form it won't return non-normalized entries.

I made a proof-of-concept parser plugin which indexes the normalized version of words.

A very short demo:

mysql> CREATE TABLE test1 (id int auto_increment primary key,
    -> txt TEXT CHARACTER SET utf8mb4, fulltext (txt));
Query OK, 0 rows affected (0.30 sec)

mysql> CREATE TABLE test2 (id int …

There was some discussion a while back to maybe make MariaDB Server follow the Ubuntu release model, i.e. having a Long Term Release (LTS) and then having a few regular fast releases with a shorter support cycle.

However its good to note that the decision now going forward is to support each and every GA release for a period of five (5) years. However, regular releases will only happen for the latest three (3) GA releases, so at this moment, you are getting updates for MariaDB Server 5.5/10.0/10.1.

Practically, we’ve not seen an update for 5.1/5.2/5.3 since 30 Jan 2013 at the time of this writing. And its clear MariaDB Server 5.5 will have an extended support policy, as it ships in Red Hat Enterprise Linux 7. 

At this time it’s worth …

MySQL Connector/Java 5.1.38 was released earlier this week, and it includes a notable improvement related to secure connections.  Here’s how the change log describes it:

When connecting to a MySQL server 5.7 instance that supports TLS, Connector/J now prefers a TLS over a plain TCP connection.

This mirrors changes made in 5.7 to the behavior of MySQL command-line clients and libmysql client library.  Coupled with the streamlined/automatic generation of TLS key material to ensure TLS availability in MySQL Server 5.7 deployments, this is an important step towards providing secure communication in default deployments.

…

MySQL Connector/Java supports connection attributes since version 5.1.25.  This projects useful metadata about the client environment into the database, where MySQL administrators can query PERFORMANCE_SCHEMA tables to remotely survey application deployment environments.  One useful piece of information exposed is the version and vendor of the JVM in use by the client.  This very short blog demonstrates how to get this information from PERFORMANCE_SCHEMA.

The metadata including the Java runtime environment version and vendor can be found in PERFORMANCE_SCHEMA.SESSION_CONNECT_ATTRS table.  Here’s the full contents of that table for a single connection from Connector/Java:

mysql> SELECT *
    -> FROM PERFORMANCE_SCHEMA.SESSION_CONNECT_ATTRS
    -> WHERE processlist_id = 31\G
*************************** 1. row ***************************
  PROCESSLIST_ID: 31
       ATTR_NAME: _runtime_version
      ATTR_VALUE: …

High memory usage scenarios may sometimes be trivial to troubleshoot e.g. when memory parameters are explicitly set too high. Investigations into such issues may also prove to be very difficult when memory pressure is a result of specific workload patterns or better yet, engine bugs.
Advanced memory troubleshooting in MySQL was never easy but thanks to performance_schema memory instrumentation in MySQL 5.7, we finally have some tools to work with. There are still situations when performance schema will not be sufficient:

1. On servers running MyQL <5.7 (well... vast majority),
2. When the component you're interested in is not instrumented,
3. When you don't fancy reading cryptic names of performance schema instruments. While I do love performance schema, this is no joke: OS-level heap profiles are much …

On December 9th, Baron Schwartz (VividCortex founder and CEO), Michele Corvino (INetU Product Manager), and Jim DeHart (INetU Systems Engineer) joined up to discuss best practices for keeping MySQL databases at peak performance. INetU – the best customer-rated cloud hosting company in the industry – knows the importance of keeping databases running without hitch. Complexity within systems increases as applications grow, which means that as complications arise, there are more risks for end users. Leveraging a database performance tool like VividCortex allows users to take care of such issues as quickly as possible, while optimizing efficiency at the same time.

Check out a recording of the webinar embedded above, or head over to INetU to register for a recording on their site and learn more. …

Next article from the MySQL 5.7 Performance stories (if missed, see 1.6M SQL Query/sec (QPS) with MySQL 5.7, 1M SQL Query/sec on mixed OLTP_RO , true Point-Selects performance and over 100K Connect/sec Rate -- all with MySQL 5.7)..

The today's article will be about re:visited MyISAM -vs- InnoDB performance comparison within MySQL 5.7 -- in fact the main and detailed article …