Hi, In our application, for LDAP Directory search operations, we are using single LDAP Handle. All threads shares this single/same LDAP Handle for all search operations. With OpenLDAP, if we use same LDAP handle for multiple threads, under the load some part of LDAP handle structure (especially ld_errno) is being shared across the threads. Due to this behavior from OpenLDAP library, we are getting -4: Decoding error.
Thread A is calling ldap_get_values API call. During ldap_get_values API call, we are trying to fetch attribute values from directory. If attribute value is empty or attribute is nor present in the directory server, OpenLDAP internal logic is updating ld_lderrno value to -4 (during ber_printf in getvalues.c at line:74). Thread B is calling ldap_search_ext_s for user lookup using same LDAP Handle. During this call, while returning "return( ldap_result2error( ld, *res, 0 ) );" from search call, it checks for ld_errno value. As this value is set to 4 by Thread A, ldap_search_ext_s API is retuning with -4 error. This is the synchronization or atomic operation issue. Under heavy load, at a particular point, sharing of ld_errno by two threads is causing the problem. Could you please check this and provide any solution that is available? As, this became critical in our application, we are blocked here. After some research, we identified that ldap_dup API can be used to solve this issue in multi threading environment. But, we are looking for production level solution for this problem. Can we use ldap_dup() to fix this issue or any other fix/solution available? Please share your inputs.
