Sartor is right, you should rolling-restart the nodes. Start with the problematic ones.
If you have multiple schemas in flight (check nodetool describecluster) you might need to take a more structured approach. Did you remove/add nodes while schema changes were in progress? ________________________________ From: Sartor Fabien (DIN) via user <user@cassandra.apache.org> Sent: 09 April 2025 13:50 To: user@cassandra.apache.org <user@cassandra.apache.org> Cc: Sartor Fabien (DIN) <fabien.sar...@etat.ge.ch> Subject: RE: Schema Version Mismatch issue EXTERNAL EMAIL - USE CAUTION when clicking links or attachments Hi Soyal, I have encountered similar issues in the past. What has consistently worked for me is performing a rolling restart of all nodes. If you don’t have tools like Ansible or scripts to automate the process, I suggest starting by restarting the node with the problematic schema. That might help resolve the issue. Another point to keep in mind: if you decommission a node, it is crucial to clear all its data, especially the system* tables. Please note that I am relatively new to Cassandra administration, so I could be mistaken. Best regards, Fabien De : Soyal Badkur <soyalbad...@gmail.com> Envoyé : mercredi, 9 avril 2025 07:00 À : user@cassandra.apache.org Objet : Schema Version Mismatch issue PRUDENCE. Ce message provient d'un expéditeur externe à l'Etat. Ne cliquez sur les liens ou n'ouvrez les pièces jointes que si vous faites entière confiance à cet expéditeur. Hi Team, We are facing issues with schema version mismatch issues in our cluster while adding new nodes. We tried decommissioning a new node as well as adding again that node in the cluster as well as we tried "nodetool resetlocalschema" to reset the schema version but it didn't work. Please help us in fixing this issue, we are currently using the 3.11.13 cassandra version. Regards, Soyal Badkur
