org.apache.kafka.clients.admin.internals.AdminMetadataManager Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kafka.clients.admin.internals;
import org.apache.kafka.clients.MetadataUpdater;
import org.apache.kafka.common.Cluster;
import org.apache.kafka.common.KafkaException;
import org.apache.kafka.common.Node;
import org.apache.kafka.common.errors.AuthenticationException;
import org.apache.kafka.common.requests.MetadataResponse;
import org.apache.kafka.common.requests.RequestHeader;
import org.apache.kafka.common.utils.LogContext;
import org.slf4j.Logger;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
/**
* Manages the metadata for KafkaAdminClient.
*
* This class is not thread-safe. It is only accessed from the AdminClient
* service thread (which also uses the NetworkClient).
*/
public class AdminMetadataManager {
private final Logger log;
/**
* The minimum amount of time that we should wait between subsequent
* retries, when fetching metadata.
*/
private final long refreshBackoffMs;
/**
* The minimum amount of time that we should wait before triggering an
* automatic metadata refresh.
*/
private final long metadataExpireMs;
/**
* Used to update the NetworkClient metadata.
*/
private final AdminMetadataUpdater updater;
/**
* The current metadata state.
*/
private State state = State.QUIESCENT;
/**
* The time in wall-clock milliseconds when we last updated the metadata.
*/
private long lastMetadataUpdateMs = 0;
/**
* The time in wall-clock milliseconds when we last attempted to fetch new
* metadata.
*/
private long lastMetadataFetchAttemptMs = 0;
/**
* The current cluster information.
*/
private Cluster cluster = Cluster.empty();
/**
* If we got an authorization exception when we last attempted to fetch
* metadata, this is it; null, otherwise.
*/
private AuthenticationException authException = null;
public class AdminMetadataUpdater implements MetadataUpdater {
@Override
public List fetchNodes() {
return cluster.nodes();
}
@Override
public boolean isUpdateDue(long now) {
return false;
}
@Override
public long maybeUpdate(long now) {
return Long.MAX_VALUE;
}
@Override
public void handleServerDisconnect(long now, String destinationId, Optional maybeFatalException) {
maybeFatalException.ifPresent(AdminMetadataManager.this::updateFailed);
AdminMetadataManager.this.requestUpdate();
}
@Override
public void handleFailedRequest(long now, Optional maybeFatalException) {
// Do nothing
}
@Override
public void handleSuccessfulResponse(RequestHeader requestHeader, long now, MetadataResponse metadataResponse) {
// Do nothing
}
@Override
public void close() {
}
}
/**
* The current AdminMetadataManager state.
*/
enum State {
QUIESCENT,
UPDATE_REQUESTED,
UPDATE_PENDING
}
public AdminMetadataManager(LogContext logContext, long refreshBackoffMs, long metadataExpireMs) {
this.log = logContext.logger(AdminMetadataManager.class);
this.refreshBackoffMs = refreshBackoffMs;
this.metadataExpireMs = metadataExpireMs;
this.updater = new AdminMetadataUpdater();
}
public AdminMetadataUpdater updater() {
return updater;
}
public boolean isReady() {
if (authException != null) {
log.debug("Metadata is not usable: failed to get metadata.", authException);
throw authException;
}
if (cluster.nodes().isEmpty()) {
log.trace("Metadata is not ready: bootstrap nodes have not been " +
"initialized yet.");
return false;
}
if (cluster.isBootstrapConfigured()) {
log.trace("Metadata is not ready: we have not fetched metadata from " +
"the bootstrap nodes yet.");
return false;
}
log.trace("Metadata is ready to use.");
return true;
}
public Node controller() {
return cluster.controller();
}
public Node nodeById(int nodeId) {
return cluster.nodeById(nodeId);
}
public void requestUpdate() {
if (state == State.QUIESCENT) {
state = State.UPDATE_REQUESTED;
log.debug("Requesting metadata update.");
}
}
public void clearController() {
if (cluster.controller() != null) {
log.trace("Clearing cached controller node {}.", cluster.controller());
this.cluster = new Cluster(cluster.clusterResource().clusterId(),
cluster.nodes(),
Collections.emptySet(),
Collections.emptySet(),
Collections.emptySet(),
null);
}
}
/**
* Determine if the AdminClient should fetch new metadata.
*/
public long metadataFetchDelayMs(long now) {
switch (state) {
case QUIESCENT:
// Calculate the time remaining until the next periodic update.
// We want to avoid making many metadata requests in a short amount of time,
// so there is a metadata refresh backoff period.
return Math.max(delayBeforeNextAttemptMs(now), delayBeforeNextExpireMs(now));
case UPDATE_REQUESTED:
// Respect the backoff, even if an update has been requested
return delayBeforeNextAttemptMs(now);
default:
// An update is already pending, so we don't need to initiate another one.
return Long.MAX_VALUE;
}
}
private long delayBeforeNextExpireMs(long now) {
long timeSinceUpdate = now - lastMetadataUpdateMs;
return Math.max(0, metadataExpireMs - timeSinceUpdate);
}
private long delayBeforeNextAttemptMs(long now) {
long timeSinceAttempt = now - lastMetadataFetchAttemptMs;
return Math.max(0, refreshBackoffMs - timeSinceAttempt);
}
/**
* Transition into the UPDATE_PENDING state. Updates lastMetadataFetchAttemptMs.
*/
public void transitionToUpdatePending(long now) {
this.state = State.UPDATE_PENDING;
this.lastMetadataFetchAttemptMs = now;
}
public void updateFailed(Throwable exception) {
// We depend on pending calls to request another metadata update
this.state = State.QUIESCENT;
if (exception instanceof AuthenticationException) {
log.warn("Metadata update failed due to authentication error", exception);
this.authException = (AuthenticationException) exception;
} else {
log.info("Metadata update failed", exception);
}
}
/**
* Receive new metadata, and transition into the QUIESCENT state.
* Updates lastMetadataUpdateMs, cluster, and authException.
*/
public void update(Cluster cluster, long now) {
if (cluster.isBootstrapConfigured()) {
log.debug("Setting bootstrap cluster metadata {}.", cluster);
} else {
log.debug("Updating cluster metadata to {}", cluster);
this.lastMetadataUpdateMs = now;
}
this.state = State.QUIESCENT;
this.authException = null;
if (!cluster.nodes().isEmpty()) {
this.cluster = cluster;
}
}
}