May 2013 - pydelion.com

27 May

Redis: “Can’t save in background: fork: Cannot allocate memory”

If you get this error

Can't save in background: fork: Cannot allocate memory

it means that your current database is bigger than memory you have. To fix the issue enable vm.overcommit_memory:

sysctl vm.overcommit_memory=1

To have if after reboot add this line to /etc/sysctl.conf:

vm.overcommit_memory=1

16 May

Create a log:

touch /var/log/mysqld-general.log

Set the permissions:

chown mysql:mysql /var/log/mysqld-general.log

Run in mysql console:

mysql> SET GLOBAL general_log_file='/var/log/mysqld-general.log';
mysql> SET GLOBAL general_log = 1;

13 May

‘show procecclist‘ can be quite long in MySQL. Here’s simple way to filer out sleeping processes:

mysql> pager grep -v  Sleep
mysql> show processlist;