| 1. Get the memcached session persistence JAR files. | |
| wget http://repo1.maven.org/maven2/de/javakaffee/msm/memcached-session-manager/1.8.2/memcached-session-manager-1.8.2.jar | |
| wget http://repo1.maven.org/maven2/de/javakaffee/msm/memcached-session-manager-tc7/1.8.2/memcached-session-manager-tc7-1.8.2.jar | |
| wget http://repo1.maven.org/maven2/net/spy/spymemcached/2.11.1/spymemcached-2.11.1.jar | |
| 2. Copy those files into the Tomcat lib folder. | |
| sudo cp memcached-session-manager-* /usr/share/tomcat7/lib | |
| sudo cp spymemcached-* /usr/share/tomcat7/lib |
| 1. Edit /etc/init.d/tomcat7 (modify for whatever version you're running) and add the following two lines: | |
| ulimit -Hn 65536 | |
| ulimit -Sn 65536 | |
| Feel free to choose whatever limit you prefer - I've simply indicated the option I chose. |
Credit for this gist goes to Alexander Rubin at https://www.percona.com/blog/author/alexanderrubin/
Article used for this was at: https://www.percona.com/blog/2017/05/08/chasing-a-hung-transaction-in-mysql-innodb-history-length-strikes-back/
To identify hung transactions:
show engine innodb status