ndimiduk commented on a change in pull request #754: HBASE-22978 : Online slow response log URL: https://github.com/apache/hbase/pull/754#discussion_r378441374
########## File path: hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/slowlog/SlowLogEventHandler.java ########## @@ -0,0 +1,150 @@ +/* + * + * 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.hadoop.hbase.regionserver.slowlog; + +import com.lmax.disruptor.EventHandler; +import com.lmax.disruptor.RingBuffer; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.List; +import java.util.Objects; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.atomic.AtomicInteger; +import java.util.concurrent.locks.Lock; +import java.util.concurrent.locks.ReentrantLock; +import java.util.stream.Collectors; + +import org.apache.yetus.audience.InterfaceAudience; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.hadoop.hbase.shaded.protobuf.generated.TooSlowLog.SlowLogPayload; + +/** + * Event Handler run by disruptor ringbuffer consumer + */ +@InterfaceAudience.Private +class SlowLogEventHandler implements EventHandler<RingBufferEnvelope> { + + private static final Logger LOG = LoggerFactory.getLogger(SlowLogEventHandler.class); + + private final SlowLogPayload[] slowLogPayloads; + + private AtomicInteger slowLogPayloadIdx = new AtomicInteger(); + + private static final Lock LOCK = new ReentrantLock(); + + private static final int WRITE_LOCK_WAIT_SEC = 1; + private static final int READ_LOCK_WAIT_SEC = 1; + + SlowLogEventHandler(int eventCount) { + this.slowLogPayloads = new SlowLogPayload[eventCount]; + } + + /** + * Called when a publisher has published an event to the {@link RingBuffer} + * + * @param event published to the {@link RingBuffer} + * @param sequence of the event being processed + * @param endOfBatch flag to indicate if this is the last event in a batch from + * the {@link RingBuffer} + * @throws Exception if the EventHandler would like the exception handled further up the chain + */ + @Override + public void onEvent(RingBufferEnvelope event, long sequence, boolean endOfBatch) + throws Exception { + SlowLogPayload slowLogPayload = event.getPayload(); + if (LOG.isTraceEnabled()) { + LOG.trace("Received Slow Log Event. RingBuffer sequence: {}, isEndOfBatch: {}, " + + "Event Call: {}", sequence, endOfBatch, + slowLogPayload.getCallDetails()); + } + try { + if (LOCK.tryLock(WRITE_LOCK_WAIT_SEC, TimeUnit.SECONDS)) { + try { + final int index = + slowLogPayloadIdx.getAndUpdate(val -> (val + 1) % slowLogPayloads.length); + slowLogPayloads[index] = slowLogPayload; + } finally { + LOCK.unlock(); + } + } else { + LOG.warn("Failed to acquire write lock while processing SlowLogEvent from RingBuffer"); + } + } catch (InterruptedException e) { + LOG.warn("Failed to acquire write lock while processing SlowLogEvent from RingBuffer", e); + } + } + + /** + * Cleans up slow log payloads + * + * @return true if slow log payloads are cleaned up, false otherwise + */ + boolean clearSlowLogs() { + if (LOG.isDebugEnabled()) { + LOG.debug("Received request to clean up online slowlog buffer.."); + } + boolean isCleanedUp = false; + try { + if (LOCK.tryLock(WRITE_LOCK_WAIT_SEC, TimeUnit.SECONDS)) { + try { + Arrays.fill(slowLogPayloads, null); + slowLogPayloadIdx.set(0); + isCleanedUp = true; + } finally { + LOCK.unlock(); + } + } else { + LOG.warn("Failed to acquire write lock while clearing slow logs"); + } + } catch (InterruptedException e) { + LOG.warn("Failed to acquire write lock while clearing slow logs", e); + } + return isCleanedUp; + } + + /** + * Retrieve list of slow log payloads + * + * @return list of slow log payloads + */ + List<SlowLogPayload> getSlowLogPayloads() { + List<SlowLogPayload> slowLogPayloadList = null; + try { + if (LOCK.tryLock(READ_LOCK_WAIT_SEC, TimeUnit.SECONDS)) { + try { + slowLogPayloadList = Arrays.stream(slowLogPayloads) + .filter(Objects::nonNull) + .collect(Collectors.toList()); + } finally { + LOCK.unlock(); + } + } else { + LOG.warn("Failed to acquire read lock while retrieving slow logs"); + } + } catch (InterruptedException e) { + throw new RuntimeException(e); Review comment: I'm not sure that throwing as a RTE is the right choice either. I think what you want to do is, at the very least, re-set the interrupt status on the current thread. Or you could modify your interface to include `throws InterruptedException` and leave it up to the caller to handle properly. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
