@Override
  public CompletableFuture<Void> decommissionRegionServers(List<ServerName> servers,
    boolean offload) {
    return this.<Void> newMasterCaller()
      .action((controller, stub) -> this.<DecommissionRegionServersRequest,
        DecommissionRegionServersResponse, Void> call(controller, stub,
          RequestConverter.buildDecommissionRegionServersRequest(servers, offload),
          (s, c, req, done) -> s.decommissionRegionServers(c, req, done), resp -> null))
      .call();
  }
Compact the region at specific region server.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java