Confluence Synchrony Service problems

[Systems Department]

Hey gang,

We are getting some strange behaviour form the Synchrony service on Confluence 6.4.1. Specifically, we started to notice a large amount of TCP connections in TIME_WAIT state. Up to 40k at some times.

Dumping the connections I notice that the synchrony service is constantly sending a [3000,"Go away!"] message to every connection it gets.

Here's a capture of one of these such sessions. There are about 20 a second.

We proxy Confluence behind Apache and have the configuration directives setup as recommended in the documentation.

POST /synchrony-proxy/sockjs/v1/491/5ku54cb5/xhr?t=1507934759990 HTTP/1.1
Host: <hidden>
Origin: <hidden>
Cookie: JSESSIONID=76DAF8D27D8F865DA9DAD2A1ED8C3647; mywork.tab.tasks=false; doc-sidebar=300px; crowd.token_key=<hidden>; _ga=GA1.2.1113231744.1503434505
Accept: */*
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/604.1.38 (KHTML, like Gecko) Version/11.0 Safari/604.1.38
Accept-Language: en-ca
Referer: https://<hidden>/pages/resumedraft.action?draftId=73892450&draftShareId=38692875-f8f2-4920-8326-2c60efdcb543
Accept-Encoding: gzip, deflate
X-Forwarded-For: 10.3.6.146
X-Forwarded-Host: <hidden>
X-Forwarded-Server: <hidden>
Connection: Keep-Alive
Content-Length: 0

HTTP/1.0 200 OK
Cache-Control: no-store, no-cache, must-revalidate, max-age=0
Content-Type: application/javascript; charset=UTF-8
Set-Cookie: JSESSIONID=76DAF8D27D8F865DA9DAD2A1ED8C3647; path=/
Access-Control-Allow-Origin: https://<hidden>
Access-Control-Allow-Credentials: true

c[3000,"Go away!"]

[Kelvin Yang]

Hi Jeremy,

We proxy Confluence behind Apache also and see a lot of time_waits (~15k) once we enable Collaborative editing. We get performance issues (confluence will hang) when Collaborative editing is turned on. Once it is turned off, everything runs smoothly.

Do you experience any performance issues with your setup using Collaborative editing?

[Edwin Kyalangalilwa]

Hi Kelvin,

Have you loaded the extra modules and additional configurations?

https://confluence.atlassian.com/confeap/using-apache-with-mod_proxy-480346967.html?_ga=2.243866309.1391339591.1517455096-1812859764.1517455096

[Kelvin Yang]

Yes, I followed the guide and everything looks to be in place.

[Edwin Kyalangalilwa]

Check for errors in the atlassian-synchrony.log in the home directory. Or is the above capture from there?

[Michael Alexander]

Did you find out more?  I get this Go Away response on the web socket and the collaborative editing doesn't work.

I have not seen anything meaningful in the atlassian-synchrony.log file. A couple lines of debug maybe regarding and event create.