org.apache.hadoop.hbase.client.RegistryEndpointsRefresher Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.client;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
import org.apache.yetus.audience.InterfaceAudience;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
/**
* Thread safe utility that keeps registry end points used by {@link ConnectionRegistry} up to date.
* By default the refresh happens periodically (configured via {@code intervalSecsConfigName}). The
* refresh can also be triggered on demand via {@link #refreshNow()}. To prevent a flood of
* on-demand refreshes we expect that any attempts two should be spaced at least
* {@code minIntervalSecsConfigName} seconds apart.
*/
@InterfaceAudience.Private
final class RegistryEndpointsRefresher {
private static final Logger LOG = LoggerFactory.getLogger(RegistryEndpointsRefresher.class);
private static final int PERIODIC_REFRESH_INTERVAL_SECS_DEFAULT = 300;
private static final int MIN_SECS_BETWEEN_REFRESHES_DEFAULT = 60;
private final Thread thread;
private final Refresher refresher;
private final long initialDelayMs;
private final long periodicRefreshMs;
private final long minTimeBetweenRefreshesMs;
private boolean refreshNow = false;
private boolean stopped = false;
synchronized void stop() {
stopped = true;
notifyAll();
}
private long getRefreshIntervalMs(boolean firstRefresh) {
if (refreshNow) {
return minTimeBetweenRefreshesMs;
}
if (firstRefresh) {
return initialDelayMs;
}
return periodicRefreshMs;
}
// The main loop for the refresh thread.
private void mainLoop() {
long lastRefreshTime = EnvironmentEdgeManager.currentTime();
boolean firstRefresh = true;
for (;;) {
synchronized (this) {
for (;;) {
if (stopped) {
LOG.info("Registry end points refresher loop exited.");
return;
}
// if refreshNow is true, then we will wait until minTimeBetweenRefreshesMs elapsed,
// otherwise wait until periodicRefreshMs elapsed
long waitTime = getRefreshIntervalMs(firstRefresh)
- (EnvironmentEdgeManager.currentTime() - lastRefreshTime);
if (waitTime <= 0) {
// we are going to refresh, reset this flag
firstRefresh = false;
refreshNow = false;
break;
}
try {
wait(waitTime);
} catch (InterruptedException e) {
LOG.warn("Interrupted during wait", e);
Thread.currentThread().interrupt();
continue;
}
}
}
LOG.debug("Attempting to refresh registry end points");
try {
refresher.refresh();
} catch (IOException e) {
LOG.warn("Error refresh registry end points", e);
}
// We do not think it is a big deal to fail one time, so no matter what is refresh result, we
// just update this refresh time and wait for the next round. If later this becomes critical,
// could change to only update this value when we have done a successful refreshing.
lastRefreshTime = EnvironmentEdgeManager.currentTime();
LOG.debug("Finished refreshing registry end points");
}
}
@FunctionalInterface
public interface Refresher {
void refresh() throws IOException;
}
private RegistryEndpointsRefresher(long initialDelayMs, long periodicRefreshMs,
long minTimeBetweenRefreshesMs, Refresher refresher) {
this.initialDelayMs = initialDelayMs;
this.periodicRefreshMs = periodicRefreshMs;
this.minTimeBetweenRefreshesMs = minTimeBetweenRefreshesMs;
this.refresher = refresher;
thread = new Thread(this::mainLoop);
thread.setName("Registry-endpoints-refresh-end-points");
thread.setDaemon(true);
thread.start();
}
/**
* Notifies the refresher thread to refresh the configuration. This does not guarantee a refresh.
* See class comment for details.
*/
synchronized void refreshNow() {
refreshNow = true;
notifyAll();
}
/**
* Create a {@link RegistryEndpointsRefresher}. If the interval secs configured via
* {@code intervalSecsConfigName} is less than zero, will return null here, which means disable
* refreshing of endpoints.
*/
static RegistryEndpointsRefresher create(Configuration conf, String initialDelaySecsConfigName,
String intervalSecsConfigName, String minIntervalSecsConfigName, Refresher refresher) {
long periodicRefreshMs = TimeUnit.SECONDS
.toMillis(conf.getLong(intervalSecsConfigName, PERIODIC_REFRESH_INTERVAL_SECS_DEFAULT));
if (periodicRefreshMs <= 0) {
return null;
}
long initialDelayMs = Math.max(1,
TimeUnit.SECONDS.toMillis(conf.getLong(initialDelaySecsConfigName, periodicRefreshMs / 10)));
long minTimeBetweenRefreshesMs = TimeUnit.SECONDS
.toMillis(conf.getLong(minIntervalSecsConfigName, MIN_SECS_BETWEEN_REFRESHES_DEFAULT));
Preconditions.checkArgument(minTimeBetweenRefreshesMs < periodicRefreshMs);
return new RegistryEndpointsRefresher(initialDelayMs, periodicRefreshMs,
minTimeBetweenRefreshesMs, refresher);
}
}