Crowd Multiple LDAP servers

[Algoteq]

I have 2 LDAP servers Primary (currently configured via ldap: chemar URL field in connector, but want to add 2nd server (LDAP Slave). Should I specify 

URL: ldap://ds1:389/ ldap://ds2:389/

instead of:

URL: ldap://ds1:389/

[Marcin Kempa · Accepted solution]

You may also give a try directory failover that Crowd offers, as described here.

Or you can go for the load balancer method as suggested by @Craig Castle-Mead.

Hope that helps,

Marcin Kempa

[Algoteq]

Crows is based on java naming service API, the URL field may contain multiple servers:

https://docs.oracle.com/javase/jndi/tutorial/ldap/misc/url.html

But it's not documented by crowd team.

[Craig Castle-Mead]

Thanks @Algoteq - was just able to get time to fully test this out and it's simplified things significantly (no need for external haproxy/lb/etc.

Used the URL format

"ldap://10.0.0.1:3268/ ldap://10.0.0.2:3268/"

Whatever the connection timeout value is, it'll check against each instance, and if there's no response, moves down the list

CCM

[Craig Castle-Mead]

I’m quite certain that the UI won’t even let you save with the double LDAP server string in the field.

I’d suggest looking at load balancing your ldap servers outside of Crowd itself (f5, AWS elb, haproxy), have Crowd point to that device and then it has the smarts to know which server to route the traffic to.

If the two servers have replication delay, you may notice some weird behavior if/when you need to fail over. Hopefully this doesn’t happen too frequently, but I’d definitely suggest testing it out on a non-prod install, or even just a new Crowd directory that isn’t linked to any of your apps. Force a failover, see what happens the next sync, fail back, test again. I’d defnintely suggest against using a round robin approach (lowers the risk of constantly adding/removing groups of the two ldaps are out of sync), only use the secondary when you have to.

CCM