Ceph » mgr

This simple program does not work (prints:)

(-13, b'', '')

If I uncomment sleep 0.1, everything works as expected.

conf = {'keyring': 'keyring.conf'}
with rados.Rados(conffile='/etc/ceph/ceph.conf', conf=conf) as cluster:
    # sleep(0.1)
    qwe = cluster.mgr_command(
        json.dumps({
            "prefix": "pg ls-by-pool",
            "poolstr": "qwe",
            "target": ["mgr", ""],
            "format": "json",
        }),
        '',
        0
    )
    print(qwe)

Ceph 12.2.4 (Ubuntu) on client, Ceph 12.2.5 (Debian) on mgr host.