In ozonesecure-ha environment SCM containers have hostnames like "scm1.org", but all Kerberos principals for SCM nodes are in the form testuser/scm@EXAMPLE.COM. Since no host named scm exists, lookup takes quite some time:
$ OZONE_LOGLEVEL=TRACE ozone sh volume create /vol1 |& grep 'lookup'
[main] TRACE security.SecurityUtil: Name lookup for om2 took 1 ms.
[main] TRACE security.SecurityUtil: Name lookup for om3 took 0 ms.
[main] TRACE security.SecurityUtil: Name lookup for om1 took 0 ms.
[main] TRACE security.SecurityUtil: Name lookup for scm took 497 ms.
We can improve this simply by executing the same commands from another container, e.g. s3g:
$ OZONE_LOGLEVEL=TRACE ozone sh volume create /vol2 |& grep 'lookup'
[main] TRACE security.SecurityUtil: Name lookup for om2 took 1 ms.
[main] TRACE security.SecurityUtil: Name lookup for om3 took 0 ms.
[main] TRACE security.SecurityUtil: Name lookup for om1 took 0 ms.
[main] TRACE security.SecurityUtil: Name lookup for s3g took 0 ms.