System error: org.hibernate.NonUniqueResultException: query did not return a unique result: 2
Asked by ofir gutmacher:

Crowd is throwing an error regards querying with Hibernate

org.hibernate.NonUniqueResultException: query did not return a unique result: 2

### Stack trace: {#toc-hId-1599556994}

`org.hibernate.NonUniqueResultException: query did not return a unique result: 2 at org.hibernate.query.internal.AbstractProducedQuery.uniqueElement(AbstractProducedQuery.java:1487) at org.hibernate.query.internal.AbstractProducedQuery.uniqueResult(AbstractProducedQuery.java:1457)`

`......`

System information {#toc-hId--756086462}
----------------------------------------

### Referer: {#toc-hId-790210368}

`http://ptkpl-crowd:8095/crowd/console/secure/directory/browse.action`

### Build information: {#toc-hId--1761946593}

**Version:**` 3.2.0 (Build:#917 - 2018-04-20)`

### Memory information: {#toc-hId--19136258}

**Total memory:**` 499 MB`  
**Free memory:**` 109 MB`  
**Used memory:**` 389 MB`

Request information: {#toc-hId-1920187582}
------------------------------------------

### Request attributes: {#toc-hId--828482884}

* **com.atlassian.johnson.filters.JohnsonFilter_already_filtered:** true
* **licencecheck.FILTERED:** true
* **javax.servlet.forward.context_path:** /crowd
* **org.springframework.web.context.request.async.WebAsyncManager.WEB_ASYNC_MANAGER:** org.springframework.web.context.request.async.WebAsyncManager@72de4058
* **(inner bean)#369e589b.FILTERED:** true
* **com.opensymphony.sitemesh.APPLIED_ONCE:** true
* **__spring_security_session_mgmt_filter_applied:** true
* **com.atlassian.crowd.integration.http.HttpAuthenticator.REQUEST_SSO_COOKIE_COMMITTED:** true
* **struts.actionMapping:** ActionMapping{name='viewconnector', namespace='/console/secure/directory', method='null', extension='action', params={}, result=null}
* **__cleanup_recursion_counter:** 1
* **__spring_security_scpf_applied:** true
* **struts.valueStack:** com.opensymphony.xwork2.ognl.OgnlValueStack@154b2999
* **struts.view_uri:** /console/500.jsp
* **javax.servlet.forward.servlet_path:** /console/secure/directory/viewconnector.action
* **javax.servlet.forward.query_string:** ID=557062
* **org.springframework.security.web.FilterChainProxy.APPLIED:** true
* **__spring_security_filterSecurityInterceptor_filterApplied:** true
* **open-session-in-view.FILTERED:** true
* **javax.servlet.forward.mapping:** org.apache.catalina.core.ApplicationMapping$MappingImpl@7f32fce4
* **B3-TraceId:** dd58363b58a149
* **struts.request_uri:** /crowd/console/secure/directory/viewconnector.action
* **crowd.token_key:** \*\*\*\*\*\*\*\*
* **javax.servlet.forward.request_uri:** /crowd/console/secure/directory/viewconnector.action
* **charsetFilter.FILTERED:** true
* **nodeInformationFilter.FILTERED:** true

### Request parameters: {#toc-hId-914327451}

* **ID:** 557062


Answers:
author: ofirgu@bezeqint.co.il
body: The Answer:  
Postgre Cluster with 2 slave databases, and 1 master.

the Crowd queries the available free pool, and updates it.

while, the master needs to query its slaves regardless of Atlassian Crowd in some timely manner.

When this situation occured:

Crowd syncs directory A, it gets into slave1 at 17:01  
Crowd syncs directory A, again, it gets into slave2 at 18:01

Postgre Master syncs to the slaves, getting 2 instances of directory A, at 19:01

Postgre master syncs the slave, pushing to them new directory A instances, at 19:02

Crowd displays log errors, because non unique directory, at 19:03

comments: author: ofirgu@bezeqint.co.il
body: Solution: I remove one of the Postgre slaves, hoping that it will not get overloaded by requests.


author: ofirgu@bezeqint.co.il
body: Im on a PostgreDB.

Ill see next week how to solve this, and add the erroneous log files to a ticket in crowd support.


author: Marcin Kempa
body: Hi [@ofir gutmacher](/t5/user/viewprofilepage/user-id/1170991)

Thanks for reporting that. Is there anything else in the log files? Without more context it is hard to figure out what may be the culprit. Crowd [support](http://getsupport.atlassian.com) should assist you with this problem.

Best Regards,

Marcin Kempa

comments: author: Marcin Kempa
body: Hi [@ofir gutmacher](/t5/user/viewprofilepage/user-id/1170991),

Did you manage to resolve the issue or contact Atlassian Support?

Are you running on MySql database? If so maybe this KB article would help you <https://confluence.atlassian.com/crowdkb/synchronization-of-crowd-results-in-error-query-did-not-return-a-unique-result-254739329.html>

Best Regards,

Marcin Kempa