This week I came across an interesting case of an update of Zimbra 7 to 8 who once the update performed, you could even access to the user or admin interface even if all services were showing green with the CLI.
Then begins the analysis of logs and unfortunately they did not provide relevant information.
When we try to make a connection, the following line appeared in /opt/zimbra/log/mailbox.log :
error while proxying request to target server: HTTP/1.1 404 Not Found.
Only in the /opt/zimbra/log/zmmailboxd.out log file that something caught my eye :
2016-06-16 06:04:22.754:WARN/service:unavailable 2016-06-16 06:04:23.754:WARN/service:unavailable javax.servlet.UnavailableException: Other filter is using the same name: com.zimbra.cs.network.license.service.ImapLicenseFilter
It seems that another library loads and takes the place of /service which has the effect of crashing any service requiring /service.
And for those who know Zimbra, the entire software uses this URL 🙁
Google obviously was dry and the only person who had the same problem never had an answer.
But looking at it more closely, in starter logs we can see that java load an unusual library:
2016-06-16 06:03:28,103 INFO [main]  extensions - extension com.zimbra.iminterop.ZimbraInteropExtension found in /opt/zimbra/lib/ext/zimbraiminterop/zimbraiminterop.jar
This is the old XMPP server library who was removed from Zimbra in version 8 but for some reason, here it still present.
So we remove this library:
then we restarts the services.
After that, I deserved a good beer!