can't add a comment to a jira ticket, keep getting communications breakdown error

Question

Trying to add a comment and get message:

Communications Breakdown

The JIRA server could not be contacted. This may be a temporary glitch or the server may be down.

This seems to happen only to me, others can add a comment without issue

On the backend I see in the logs :

Error closing Connection java.sql.SQLException: Already closed.

Jira is jira server (not cloud) v 7.0.4

I've gone through all the suggestions found here : Surviving connection closures | Administering Jira applications Data Center and Server 7.3 | Atlassian Documentation but this did not help (even setting test-on-borrow to true).

I am suspecting that there is something with my session or account as others are not having issues. I tried logging out, rebooting, clearing browser cache but all to no avail.  I have restarted mysql and jira as well as the server and this issue is still there.

I have tried adding comments to multiple issues which all fail.  I created a new ticket but i could not comment on it afterwards either.

lada77 · Accepted Answer

Finally got this fixed. Documenting here to help others. Added : 40 to dbconfig.xml and set the number to be equal to pool-max-size setting Note mysql for us was on same server. Stopped jira and mysql Did backup copy of mysql : cp -rp /var/lib/mysql /var/lib/mysql.bk Started mysql again and exported database /usr/bin/mysqldump -u root -p -R -E --triggers --single-transaction jiradb > jiradb.sql Went into mysql and dropped the database drop database jiradb; create database jiradb; Imported database mysql -u root -p jiradb < jiradb.sql started jira And now i can add comments again.