# 2022-04-24-11:15:04+0800 Migrate dev tier cluster to SEM

- Cause: https://jira.tidbcloud.com/browse/DM-4992

- Operation:

By investigating Thanos metrics, we found the following dev tier clusters have extra-tidb

{namespace="free-tier-prod-1372813089188721288", pod="db1379661944593544070-tidb-extra-access-c797dccb5-l49nk"}
{namespace="free-tier-prod-1372813089188781283", pod="db1379661944599604066-tidb-extra-access-644b568d7c-nvf45"}
{namespace="free-tier-prod-1372813089188931282", pod="db1379661944584964073-tidb-extra-access-68b5584f9-5frms"}
{namespace="free-tier-prod-1372813089189051306", pod="db1379661944586044065-tidb-extra-access-5f5c46ddd6-vlbzd"}
{namespace="free-tier-prod-1372813089190251286", pod="db1379661944597174072-tidb-extra-access-57d75fc999-m999d"}

And these clusters tidb version is 5.4 which > 5.3, so they are created before the SEM feature released to prod, so they need to migrate to SEM

By using the migrate program provided by https://github.com/tidbcloud/dbaas/pull/5171, and the procedures, we can migrate all the above dev tier clusters.

- Impact:

The dev tier clusters will be restarted and using security enhanced mode

- Recovery operation:

N/A

- Time window: