Disclaimer

As Bitbucket Data Center applications are using the load balancer both on the application (HTTPS) and transport (SSH) levels it is strongly recommended to use the load balancer software capable of performing a load balancing on both levels. Until usage of mod_proxy_balancer is not the requirement we recommend you to use the HAProxy as mentioned in the documentation.

mod_proxy_balancer examples

Bitbucket DC requires sticky HTTP sessions. Using a cookie strategy approach for this will give you more control over user IP changes that occur due to network or VPN configuration.

mod_proxy_balancer with specific cookie

This is the less intrusive approach where your load balancer creates a specific cookie to route all the requests from the same session to the same backend server.
In this example, we will instruct Apache to create a cookie called ROUTEID, and use it for stickysession.

Header add Set-Cookie "ROUTEID=.%{BALANCER_WORKER_ROUTE}e; path=/" env=BALANCER_ROUTE_CHANGED

<Proxy balancer://bitbucketcluster>

    BalancerMember http://backend1:7990 route=perftest1

    BalancerMember http://backend2:7990 route=perftest2

</Proxy>

ProxySet stickysession=ROUTEID
ProxyPass / balancer://bitbucketcluster/ lbmethod=byrequests stickysession=ROUTEID
ProxyPreserveHost On

In that case when the user is connected to Bitbucket DC the following cookies are getting set:

BITBUCKETSESSIONID

Tomcat BITBUCKETSESSIONID cookie

Tomcat supports routing information in the BITBUCKETSESSIONID cookie when you start with -DjvmRoute=<nodeName> parameter. This information is also used by Apache.

<Proxy balancer://bitbucketcluster>
    BalancerMember http://backend1:7990 route=perftest1
    BalancerMember http://backend2:7990 route=perftest2
</Proxy>
ProxyPass / balancer://bitbucketcluster/ stickysession=BITBUCKETSESSIONID

In that case when the user is connected to Bitbucket DC the following cookies are getting set:

BITBUCKETSESSIONID

Note that the route information is added as a suffix on BITBUCKETSESSIONID value