Set heartbeat via command line in hadoop - hadoop

Question

It is possible to set the heartbeat of the nodemanager parameter via command line in hadoop ?
How ?
In alternative is possible to modify such parameter without restart the cluster ?
The parameter I am interested in manage is yarn.resourcemanager.nodemanagers.heartbeat-interval-ms under yarn-default.xml

Answer 1

You cannot set this parameter yarn.resourcemanager.nodemanagers.heartbeat-interval-ms (indicates The heart-beat interval in milliseconds for every NodeManager in the cluster.) using command line.
You can change this parameter in yarn-site.xml and then you need to re-start the services.
The reason being, this parameter is read once, when the Resource Tracker Service is started in the Resource Manager. The heart beat interval is returned to the Node Manager, as part of NodeHeartbeatResponse.
// Heartbeat response
NodeHeartbeatResponse nodeHeartBeatResponse = YarnServerBuilderUtils
.newNodeHeartbeatResponse(lastNodeHeartbeatResponse.
getResponseId() + 1, NodeAction.NORMAL, null, null, null, null,
nextHeartBeatInterval);
The parameter nextHeartBeatInterval in the call above, is read in serviceInit() method of Resource Tracker Service:
nextHeartBeatInterval =
conf.getLong(YarnConfiguration.RM_NM_HEARTBEAT_INTERVAL_MS,
YarnConfiguration.DEFAULT_RM_NM_HEARTBEAT_INTERVAL_MS);
if (nextHeartBeatInterval <= 0) {
throw new YarnRuntimeException("Invalid Configuration. "
+ YarnConfiguration.RM_NM_HEARTBEAT_INTERVAL_MS
+ " should be larger than 0.");
}
Also, the value of yarn.resourcemanager.nodemanagers.heartbeat-interval-ms (default 1000) should be less than value of yarn.nm.liveness-monitor.expiry-interval-ms (default 600000). yarn.nm.liveness-monitor.expiry-interval-ms indicates How long to wait until a node manager is considered dead..
The check for this is in validateConfigs() method of the Resource Manager:
// validate expireIntvl >= heartbeatIntvl
long expireIntvl = conf.getLong(YarnConfiguration.RM_NM_EXPIRY_INTERVAL_MS,
YarnConfiguration.DEFAULT_RM_NM_EXPIRY_INTERVAL_MS);
long heartbeatIntvl =
conf.getLong(YarnConfiguration.RM_NM_HEARTBEAT_INTERVAL_MS,
YarnConfiguration.DEFAULT_RM_NM_HEARTBEAT_INTERVAL_MS);
if (expireIntvl < heartbeatIntvl) {
throw new YarnRuntimeException("Nodemanager expiry interval should be no"
+ " less than heartbeat interval, "
+ YarnConfiguration.RM_NM_EXPIRY_INTERVAL_MS + "=" + expireIntvl
+ ", " + YarnConfiguration.RM_NM_HEARTBEAT_INTERVAL_MS + "="
+ heartbeatIntvl);
}