lefred

lefred

I am MySQL Community Manager for EMEA & APAC. I joined the MySQL Community Team in May 2016. I have been an OpenSource and MySQL consultant for more than 15 years. My favorite topics are High Availability and Performance.
  • Joined: April 26, 2016
  • Articles: 608
  • Comments: 373

MySQL proxies

I've tested last night two proxies for MySQL : MySQL-Proxy and Dormando's Proxy for MySQL.

Both are working, but I still don't see really the advantage of using DPM over MySQL-Proxy, maybe I should make more tests but deploying MySQL-Proxy was easier as you define the backends as arguments in command line.

I plan to use a MySQL proxy in production as load-balancer in combination with replication and redirect all DML queries to the master.

Does one of you already use one of those two projects in production, what's your feedback ?

You can also find more information on DLM here.

It would be maybe nice to have a kind of buffer if for any reasons the backends servers are not responding ?

Nagios JBoss Check

As I had to monitor some JBoss servers and as there are some memory leaks in the program, the monitoring in Nagios of the Garbage Collector is very important. I've found some jmx script on JBoss wiki, but I was not happy with it. So I rewrite it to use twiddle.sh with the attributes I needed.

I had also to modify twiddle.sh to remove the logging capability (that was causing permission error) :

# diff twiddle.sh twiddleFred.sh
58c58
< JBOSS_CLASSPATH="$JBOSS_CLASSPATH:$JBOSS_HOME/client/log4j.jar"
---
> # removed to avoid log file JBOSS_CLASSPATH="$JBOSS_CLASSPATH:$JBOSS_HOME/client/log4j.jar"

Those are the nrpe test I implemented :

# check Perm Gen
command[check_jbosspem]=/usr/lib/nagios/plugins/check_jbosspem 127.0.0.1 4 jboss.system:type=ServerInfo listMemoryPools "Perm Gen" 70 90

# check Old Gen (Heap Memory)
command[check_jbossoldgen]=/usr/lib/nagios/plugins/check_jbosspem 127.0.0.1 4 jboss.system:type=ServerInfo listMemoryPools "Old Gen" 85 95

Tip: vi and lowercase/uppercase

As always I use my blog as reminder of some useful commands or tips.

This one is for dimi, to change the case of a full document in vi, use the following command to transform everything in lowercase :


<ESC>:%s/.*/\L&/

and in uppercase :

<ESC>:%s/.*/\U&/

I hope this helps ;)

As MySQL Community Manager, I am an employee of Oracle and the views expressed on this blog are my own and do not necessarily reflect the views of Oracle.

You can find articles I wrote on Oracle’s blog.

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