HDDS-839 we had a hard-coded 15 seconds sleep before we started ozoneManager with the docker-compose files (hadoop-ozone/dist/target/ozone-0.4.0-SNAPSHOT/compose).
For initialization of the OzoneManager we need the scm. Om will retry the connection if scm is not available but the dns resolution is cached: if the dns of scm is not available at the startup of om, it can't be initialized.
HDDS-839 we handled this dependency with the 15 seconds sleep, which was usually slower what we need.
Now we can use the WAITFOR environment variables from
HDDS-839 to handle this dependency (like WAITFOR:scmL9876) which can be added to all the docker-compose files.