/**
* Fetches all of the latest heartbeats and updates the Cluster Coordinator as appropriate, based
* on the heartbeats received.
*
* <p>Visible for testing.
*/
protected synchronized void monitorHeartbeats() {
final Map<NodeIdentifier, NodeHeartbeat> latestHeartbeats = getLatestHeartbeats();
if (latestHeartbeats == null || latestHeartbeats.isEmpty()) {
logger.debug(
"Received no new heartbeats. Will not disconnect any nodes due to lack of heartbeat");
return;
}
final StopWatch procStopWatch = new StopWatch(true);
for (final NodeHeartbeat heartbeat : latestHeartbeats.values()) {
try {
processHeartbeat(heartbeat);
} catch (final Exception e) {
clusterCoordinator.reportEvent(
null,
Severity.ERROR,
"Received heartbeat from "
+ heartbeat.getNodeIdentifier()
+ " but failed to process heartbeat due to "
+ e);
logger.error(
"Failed to process heartbeat from {} due to {}",
heartbeat.getNodeIdentifier(),
e.toString());
logger.error("", e);
}
}
procStopWatch.stop();
logger.info(
"Finished processing {} heartbeats in {}",
latestHeartbeats.size(),
procStopWatch.getDuration());
// Disconnect any node that hasn't sent a heartbeat in a long time (8 times the heartbeat
// interval)
final long maxMillis = heartbeatIntervalMillis * 8;
final long threshold = System.currentTimeMillis() - maxMillis;
for (final NodeHeartbeat heartbeat : latestHeartbeats.values()) {
if (heartbeat.getTimestamp() < threshold) {
clusterCoordinator.requestNodeDisconnect(
heartbeat.getNodeIdentifier(),
DisconnectionCode.LACK_OF_HEARTBEAT,
"Latest heartbeat from Node has expired");
try {
removeHeartbeat(heartbeat.getNodeIdentifier());
} catch (final Exception e) {
logger.warn(
"Failed to remove heartbeat for {} due to {}",
heartbeat.getNodeIdentifier(),
e.toString());
logger.warn("", e);
}
}
}
}
private void processHeartbeat(final NodeHeartbeat heartbeat) {
final NodeIdentifier nodeId = heartbeat.getNodeIdentifier();
// Do not process heartbeat if it's blocked by firewall.
if (clusterCoordinator.isBlockedByFirewall(nodeId.getSocketAddress())) {
clusterCoordinator.reportEvent(
nodeId,
Severity.WARNING,
"Firewall blocked received heartbeat. Issuing disconnection request.");
// request node to disconnect
clusterCoordinator.requestNodeDisconnect(
nodeId, DisconnectionCode.BLOCKED_BY_FIREWALL, "Blocked by Firewall");
removeHeartbeat(nodeId);
return;
}
final NodeConnectionStatus connectionStatus = clusterCoordinator.getConnectionStatus(nodeId);
if (connectionStatus == null) {
// Unknown node. Issue reconnect request
clusterCoordinator.reportEvent(
nodeId,
Severity.INFO,
"Received heartbeat from unknown node. Removing heartbeat and requesting that node connect to cluster.");
removeHeartbeat(nodeId);
clusterCoordinator.requestNodeConnect(nodeId, null);
return;
}
final NodeConnectionState connectionState = connectionStatus.getState();
if (heartbeat.getConnectionStatus().getState() != NodeConnectionState.CONNECTED
&& connectionState == NodeConnectionState.CONNECTED) {
// Cluster Coordinator believes that node is connected, but node does not believe so.
clusterCoordinator.reportEvent(
nodeId,
Severity.WARNING,
"Received heartbeat from node that thinks it is not yet part of the cluster,"
+ "though the Cluster Coordinator thought it was (node claimed state was "
+ heartbeat.getConnectionStatus().getState()
+ "). Marking as Disconnected and requesting that Node reconnect to cluster");
clusterCoordinator.requestNodeConnect(nodeId, null);
return;
}
if (NodeConnectionState.DISCONNECTED == connectionState) {
// ignore heartbeats from nodes disconnected by means other than lack of heartbeat, unless it
// is
// the only node. We allow it if it is the only node because if we have a one-node cluster,
// then
// we cannot manually reconnect it.
final DisconnectionCode disconnectionCode = connectionStatus.getDisconnectCode();
// Determine whether or not the node should be allowed to be in the cluster still, depending
// on its reason for disconnection.
if (disconnectionCode == DisconnectionCode.LACK_OF_HEARTBEAT
|| disconnectionCode == DisconnectionCode.UNABLE_TO_COMMUNICATE) {
clusterCoordinator.reportEvent(
nodeId,
Severity.INFO,
"Received heartbeat from node previously "
+ "disconnected due to "
+ disconnectionCode
+ ". Issuing reconnection request.");
clusterCoordinator.requestNodeConnect(nodeId, null);
} else {
// disconnected nodes should not heartbeat, so we need to issue a disconnection request.
logger.info(
"Ignoring received heartbeat from disconnected node "
+ nodeId
+ ". Issuing disconnection request.");
clusterCoordinator.requestNodeDisconnect(
nodeId,
DisconnectionCode.HEARTBEAT_RECEIVED_FROM_DISCONNECTED_NODE,
DisconnectionCode.HEARTBEAT_RECEIVED_FROM_DISCONNECTED_NODE.toString());
removeHeartbeat(nodeId);
}
return;
}
if (NodeConnectionState.DISCONNECTING == connectionStatus.getState()) {
// ignore spurious heartbeat
removeHeartbeat(nodeId);
return;
}
// first heartbeat causes status change from connecting to connected
if (NodeConnectionState.CONNECTING == connectionState) {
final Long connectionRequestTime = connectionStatus.getConnectionRequestTime();
if (connectionRequestTime != null && heartbeat.getTimestamp() < connectionRequestTime) {
clusterCoordinator.reportEvent(
nodeId,
Severity.INFO,
"Received heartbeat but ignoring because it was reported before the node was last asked to reconnect.");
removeHeartbeat(nodeId);
return;
}
// connection complete
clusterCoordinator.finishNodeConnection(nodeId);
clusterCoordinator.reportEvent(
nodeId, Severity.INFO, "Received first heartbeat from connecting node. Node connected.");
}
clusterCoordinator.updateNodeRoles(nodeId, heartbeat.getRoles());
}