Problem: No one query was executing on server and hang on server from long time also not executing any new queries.
Steps to Track the reason:
As all queries are not executing and in hanging state, so first need to check server error logs. You can use below command on linux server.
tail -n25 /var/log/mysqld.log
Note: where mysqld.log is error log file, so change name as per your log file. You can check its name and exact location from my.cnf file.
If it is showing error like below, it means space has been finished on server where binlog exist-
[ERROR] /usr/libexec/mysqld: Disk is full writing ‘./mysql-bin.000092′ (Errcode: 28). Waiting for someone to free space… Retry in 60 secs
Solution: You need to create some space in that partition.
Cross-checking: You need to cross check you replication if using.
Replication Issue: If you are getting replication fail then just execute below commands to restart slave service.
If still replication does not start then need to trouble shoot for reason. You can check possible solution in Replication Trouble Shooting section.