kafka AdminClient 閑時關閉連接
阿新 • • 發佈:2019-01-18
lru enabled sel strace trac cto mon expire The
AdminClient 類提供了創建 topic,刪除 topic 的 api。
在項目中創建了一個 AdminClient 對象,每次創建 topic 時,調用
org.apache.kafka.clients.admin.AdminClient#createTopics
如果長時間不使用這個對象,客戶端與 broker 之間的連接會被關掉,相關的參數:
connections.max.idle.ms
這個最大空閑參數在 broker 和 客戶端都可以配置,即 broker 和客戶端都會關閉空閑太久的連接。
org.apache.kafka.common.network.Selector#maybeCloseOldestConnection
private void maybeCloseOldestConnection(long currentTimeNanos) { if (idleExpiryManager == null) return; Map.Entry<String, Long> expiredConnection = idleExpiryManager.pollExpiredConnection(currentTimeNanos); if (expiredConnection != null) { String connectionId= expiredConnection.getKey(); KafkaChannel channel = this.channels.get(connectionId); if (channel != null) { if (log.isTraceEnabled()) log.trace("About to close the idle connection from {} due to being idle for {} millis", connectionId, (currentTimeNanos- expiredConnection.getValue()) / 1000 / 1000); channel.state(ChannelState.EXPIRED); close(channel, CloseMode.GRACEFUL); } } }
org.apache.kafka.common.network.Selector.IdleExpiryManager#pollExpiredConnection
public Map.Entry<String, Long> pollExpiredConnection(long currentTimeNanos) { if (currentTimeNanos <= nextIdleCloseCheckTime) return null; if (lruConnections.isEmpty()) { nextIdleCloseCheckTime = currentTimeNanos + connectionsMaxIdleNanos; return null; } Map.Entry<String, Long> oldestConnectionEntry = lruConnections.entrySet().iterator().next(); Long connectionLastActiveTime = oldestConnectionEntry.getValue(); nextIdleCloseCheckTime = connectionLastActiveTime + connectionsMaxIdleNanos; if (currentTimeNanos > nextIdleCloseCheckTime) return oldestConnectionEntry; else return null; }
kafka AdminClient 閑時關閉連接