Hello Tomas, thank you for the fast response. There is nothing out of the ordinary in the keycloak or database logs. To add some information: We use the version 4.5 of Keycloak and a Postgres DB to store the data. Both running in Docker containers. We tried it from a different system (also a Docker container) that uses Feign clients to comunicate with Keycloak and have no problems there. On the same system where we wanted to use the keycloak-admin-client we tried it with RestTemplates and had no problems either. I think that rules out the database as a possible bottleneck. It would be great if you have any other idea or suggestion where we should take a look. If we don't find another solution we will use RestTemplates but the abmin-client would be way more convenient. ;-) Kind regards Jan ________________________________ Von: Tomas Kyjovsky <tkyjovsk(a)redhat.com&gt; Gesendet: Donnerstag, 14. März 2019 00:21:50 An: Lengenfeld, Jan Cc: keycloak-user(a)lists.jboss.org Betreff: Re: [keycloak-user] Performance issues when creating users with keycloak-admin-client Hello Jan, I'm not aware of any issues. This should work normally. We are using the REST client to generate data for our performance testing. I've just tried and successully generated 10k users in about 1 minute (with the current upstream/master version of the project). Can you check configuration of your data source connection pool? In our performace testing we use MariaDB datasource with: min-pool-size=10, max-pool-size=100, prefill=true, flush-strategy=IdleConnections, prepared-statement-cache-size=100. Does Keycloak server log give any hints about what could be going wrong there? Or perhaps your database server log? Tomas Kyjovsky ----- Original Message -----