[FLUME-1248] flume-ng script gets broken when it tried to load hbase classpath

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.1.0
• Fix Version/s: 1.2.0
• Component/s: Shell
• Assignee: Will McQueen
• Reporter: Mingjie Lai
• Created: 31/May/12 21:09
• Updated: 18/Jun/12 23:26
• Resolved: 18/Jun/12 23:00

Description

bin/flume-ng tried to load hbase/hadoop class path by this:

103     local HBASE_CLASSPATH=""
104     local HBASE_JAVA_LIBRARY_PATH=$(HBASE_CLASSPATH="$FLUME_CLASSPATH" \
105         ${HBASE_IN_PATH} org.apache.flume.tools.GetJavaProperty \
106         java.library.path 2>/dev/null)

It actually turned out to be:

$ hbase -cp ../lib/flume-ng-core-1.2.0-incubating-SNAPSHOT.jar \
  org.apache.flume.tools.GetJavaProperty  java.library.path

However what I saw is:

-bash-3.2$ hbase -cp ../lib/flume-ng-core-1.2.0-incubating-SNAPSHOT.jar   org.apache.flume.tools.GetJavaProperty  java.library.path
/usr/lib/hadoop-0.20/lib/native/Linux-amd64-64:/usr/lib/hbase/bin/../lib/native/Linux-amd64-64
Heap
 par new generation   total 235968K, used 8391K [0x00000002fae00000, 0x000000030ae00000, 0x000000030ae00000)
  eden space 209792K,   4% used [0x00000002fae00000, 0x00000002fb631f30, 0x0000000307ae0000)
  from space 26176K,   0% used [0x0000000307ae0000, 0x0000000307ae0000, 0x0000000309470000)
  to   space 26176K,   0% used [0x0000000309470000, 0x0000000309470000, 0x000000030ae00000)
 concurrent mark-sweep generation total 20709376K, used 0K [0x000000030ae00000, 0x00000007fae00000, 0x00000007fae00000)
 concurrent-mark-sweep perm gen total 21248K, used 2724K [0x00000007fae00000, 0x00000007fc2c0000, 0x0000000800000000)

The hbase gc info outputs to stdout and screwed up the flume-ng script.

The root cause is the combination of several factors:
1. turn on hbase gc log by:

export HBASE_OPTS="$HBASE_OPTS -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCDateS
tamps -Xloggc:$HBASE_HOME/logs/gc-hbase.log" 

2. the gc log directory is protected by limiting the permission as 755, and owned by hbase user.

3. use another user, such as flume, to execute the script.

Since flume user doesn't have write permission to the hbase gc log directory, jvm will output the gc info to stdout, and the flume script will be screwed up.

A simple but tricky fix could be adding ``grep hbase'' in the scrip to filter out the gc info:

103     local HBASE_CLASSPATH=""
104     local HBASE_JAVA_LIBRARY_PATH=$(HBASE_CLASSPATH="$FLUME_CLASSPATH" \
105         ${HBASE_IN_PATH} org.apache.flume.tools.GetJavaProperty \
106         java.library.path | grep hbase 2>/dev/null)

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