ZOOKEEPER-3712: Add setKeepAlive support for NIOServerCnxn.
Author: Fangxi Yin <yinfangxikuaishou.com>
Author: yinfangxi <yinfangxi@kuaishou.com>
Reviewers: Michael Han <hanm@apache.org>, Justin Ling Mao <maoling199210191@sina.com>
Closes #1242 from yfxhust/ZOOKEEPER-3712
diff --git a/zookeeper-docs/src/main/resources/markdown/zookeeperAdmin.md b/zookeeper-docs/src/main/resources/markdown/zookeeperAdmin.md
index 6b6113f..fd5b95d 100644
--- a/zookeeper-docs/src/main/resources/markdown/zookeeperAdmin.md
+++ b/zookeeper-docs/src/main/resources/markdown/zookeeperAdmin.md
@@ -1335,7 +1335,23 @@
properly, check your operating system's options regarding TCP
keepalive for more information. Defaults to
**false**.
-
+
+* *clientTcpKeepAlive* :
+ (Java system property: **zookeeper.clientTcpKeepAlive**)
+ **New in 3.6.1:**
+ Setting this to true sets the TCP keepAlive flag on the
+ client sockets. Some broken network infrastructure may lose
+ the FIN packet that is sent from closing client. These never
+ closed client sockets cause OS resource leak. Enabling this
+ option terminates these zombie sockets by idle check.
+ Enabling this option relies on OS level settings to work
+ properly, check your operating system's options regarding TCP
+ keepalive for more information. Defaults to **false**. Please
+ note the distinction between it and **tcpKeepAlive**. It is
+ applied for the client sockets while **tcpKeepAlive** is for
+ the sockets used by quorum members. Currently this option is
+ only available when default `NIOServerCnxnFactory` is used.
+
* *electionPortBindRetry* :
(Java system property only: **zookeeper.electionPortBindRetry**)
Property set max retry count when Zookeeper server fails to bind
diff --git a/zookeeper-server/src/main/java/org/apache/zookeeper/server/NIOServerCnxn.java b/zookeeper-server/src/main/java/org/apache/zookeeper/server/NIOServerCnxn.java
index 9cde078..2ed7589 100644
--- a/zookeeper-server/src/main/java/org/apache/zookeeper/server/NIOServerCnxn.java
+++ b/zookeeper-server/src/main/java/org/apache/zookeeper/server/NIOServerCnxn.java
@@ -81,6 +81,11 @@ public class NIOServerCnxn extends ServerCnxn {
*/
private long sessionId;
+ /**
+ * Client socket option for TCP keepalive
+ */
+ private final boolean clientTcpKeepAlive = Boolean.getBoolean("zookeeper.clientTcpKeepAlive");
+
public NIOServerCnxn(ZooKeeperServer zk, SocketChannel sock, SelectionKey sk, NIOServerCnxnFactory factory, SelectorThread selectorThread) throws IOException {
super(zk);
this.sock = sock;
@@ -93,6 +98,7 @@ public NIOServerCnxn(ZooKeeperServer zk, SocketChannel sock, SelectionKey sk, NI
sock.socket().setTcpNoDelay(true);
/* set socket linger to false, so that socket close does not block */
sock.socket().setSoLinger(false, -1);
+ sock.socket().setKeepAlive(clientTcpKeepAlive);
InetAddress addr = ((InetSocketAddress) sock.socket().getRemoteSocketAddress()).getAddress();
addAuthInfo(new Id("ip", addr.getHostAddress()));
this.sessionTimeout = factory.sessionlessCnxnTimeout;
