Locally change the log level for the zookeeper C client

Question

I'm using Apache Spark's spark-shell with mesos and zookeeper, which seems to working well except that I'm getting more logging from zookeeper than I'd like, which is a bit distracting:

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Using Scala version 2.10.4 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_60)
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2015-03-26 20:08:22,115:15978(0x7f83a1fbc740):ZOO_INFO@log_env@712: Client environment:zookeeper.version=zookeeper C client 3.4.6
2015-03-26 20:08:22,115:15978(0x7f83a1fbc740):ZOO_INFO@log_env@716: Client environment:host.name=myhost
2015-03-26 20:08:22,115:15978(0x7f83a1fbc740):ZOO_INFO@log_env@723: Client environment:os.name=Linux
2015-03-26 20:08:22,115:15978(0x7f83a1fbc740):ZOO_INFO@log_env@724: Client environment:os.arch=3.2.0-34-generic
2015-03-26 20:08:22,115:15978(0x7f83a1fbc740):ZOO_INFO@log_env@725: Client environment:os.version=#53-Ubuntu SMP Thu Nov 15 10:48:16 UTC 2012
2015-03-26 20:08:22,115:15978(0x7f83a1fbc740):ZOO_INFO@log_env@733: Client environment:user.name=myname
2015-03-26 20:08:22,115:15978(0x7f83a1fbc740):ZOO_INFO@zookeeper_init@786: Initiating client connection, host=localhost:9999 sessionTimeout=10000 watcher=0xffffffffff sessionId=0 sessionPasswd=<null> context=0x777777777777 flags=0
2015-03-26 20:08:22,115:15978(0x7f83a1fbc740):ZOO_INFO@check_events@1703: initiated connection to server [127.0.0.1:9999]
2015-03-26 20:08:22,115:15978(0x7f83a1fbc740):ZOO_INFO@check_events@1750: session establishment complete on server [127.0.0.1:9999], sessionId=0x11111111111111, negotiated timeout=10000
Spark context available as sc.
SQL context available as sqlContext.

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I've tried changing $SPARK_CONF_DIR/log4j.properties

log4j.logger.org.apache.zookeeper=WARN

Which didn't work, but I'm not surprised since the mesos documentation mentions that the zookeeper logging goes directly to stderr:

NOTE: 3rd party log messages (e.g. ZooKeeper) are only written to stderr!

Adding a jar to spark's classpath that has a static block with a foreign-function interface call to the zookeeper C api function to change the log level seems like it might work, but I'm not sure, and I don't have any experience with calling C code from the JVM.

Enucleate

Answer 1

In addition to,

log4j.logger.org.apache.zookeeper=WARN

also configure the stderr log-level to print only logs with priority ERROR (and above).

# Send WARN or higher to stderr
log4j.appender.stderr = org.apache.log4j.ConsoleAppender
log4j.appender.stderr.Threshold = ERROR
log4j.appender.stderr.Target = System.err

---

Also a LevelRangeFilter might also prove useful as shown here.

Sternutatory

Nope, this made no difference to the zookeeper's ZOO_INFO logs, which are still spitting out on stderr. – Enucleate

Answer 2

Couldn't find anything on this either, but for JNI (Java-to-C) can offer this. Looks like neither zookeeper not mesos have web service or shells (zookeeper has zkshell though, but not usable in our case) that can be used.

Volpe