We're using the ldap from gwadminservice in gw2014 r2sp1hp1 to enable authentication for our mail security company (mimecast). We've seen it fail at certain times of the day, mostly after midnight. Logging normally looks something like this:
GwLdapAuthenticationInterceptor [ERROR] Error binding mchammer.lapox.xxx_CENTRAL
com.novell.gw.api.common.GwRuntimeException: javax.naming.ServiceUnavailableException: Failed connecting to the POA at lapox.xxx.org.
at com.novell.gw.api.domain.DomainConnection.getUserC lientConnectionFull(DomainConnection.java:2068)
at com.novell.gw.api.gwobject.GwConnection.connectToU serAccountFull(GwConnection.java:345)
at com.novell.gw.ldap.server.GwLdapDomainConnection.g etUserConnectionId(GwLdapDomainConnection.java:510 )
at com.novell.gw.ldap.server.GwLdapAuthenticationInte rceptor.bind(GwLdapAuthenticationInterceptor.java: 147)
at org.apache.directory.server.core.DefaultOperationM anager.bind(DefaultOperationManager.java:439)
at org.apache.directory.server.ldap.handlers.request. BindRequestHandler.handleSimpleAuth(BindRequestHan dler.java:184)
at com.novell.gw.ldap.server.GwLdapBindRequestHandler .handleSimpleAuth(GwLdapBindRequestHandler.java:63 )
at org.apache.directory.server.ldap.handlers.request. BindRequestHandler.handle(BindRequestHandler.java: 636)
at com.novell.gw.ldap.server.GwLdapBindRequestHandler .handle(GwLdapBindRequestHandler.java:50)

I wrote a script to test for ldap responses, mchammer in this example is the test account. The error is most often a result of my user being unable to authenticate like this. It doesn't matter which of my POs the account is in. The POA logs show nothing irregular at tis time. Any ideas what could be causing it to fail?

If anyone wants to see my script let me know, I'm willing to share.