The bounty expires in 7 days. Answers to this question are eligible for a +200 reputation bounty. NG. wants to draw more attention to this question. I am trying to implement pagination in LDAP using vlv, using reference from document https://docs.ldap.com/ldap-sdk/docs/javadoc/com/unboundid/ldap/sdk/contro... it is working fine with single thread, but when try with multiple threads concurrently upto 5 threads it works fine, but as number of threads increased only 5 threads can run successfully exceed threads got failed with below error message: LDAPException(resultCode=51 (busy), numEntries=0, numReferences=0, diagnostiMessage='Other sort requests already in progress', ldapSDKVersion=5.1.1.. I am using OpenLDAP, Unboundid api for connection with Java. About data size it is around 100k.> Tried with single connection and multiple connections(with multiple concurrent threads) getting same error in both cases. Tried to synchronize block for fetching data. On exception, make thread to wait and try again. All above things didn't worked, threads cannot fetch data from LDAP. After trying to close and reconnect connection as described in https://www.openldap.org/lists/openldap-technical/201107/msg00006.html failed thread can fetch data but after retry lot of times, in my case thread retried about 2k times then it started fetching data. Is there any better solution, retrying 2k times and getting result is not a good option.