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Date: Wed, 02 Apr 2008 16:36:55 +0800
From: Yingyuan Cheng <yingyuan@staff.sina.com.cn>
Subject: Help: libhdfs SIGSEGV
To: hadoop-user@lucene.apache.org
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Hello.

Is libhdfs thread-safe? I can run single thread reading/writing HDFS
through libhdfs well, but when incrementing number of threads to 2 or
above, I received sigsegv error:

#
# An unexpected error has been detected by Java Runtime Environment:
#
# Internal Error (53484152454432554E54494D450E4350500214), pid=15614,
tid=1080834960
#
# Java VM: Java HotSpot(TM) Server VM (1.6.0_03-b05 mixed mode)
# An error report file with more information is saved as hs_err_pid15614.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#
/bin/sh: line 1: 15614 Aborted ./hdfsbench -a w /tmp/test/txt -t 2


and the bt output:


(gdb) bt full
#0 0x061707b8 in ChunkPool::allocate () from
/usr/lib/jvm/java/jre/lib/i386/server/libjvm.so
No symbol table info available.
#1 0x061703a6 in Arena::Arena () from
/usr/lib/jvm/java/jre/lib/i386/server/libjvm.so
No symbol table info available.
#2 0x06501729 in Thread::Thread () from
/usr/lib/jvm/java/jre/lib/i386/server/libjvm.so
No symbol table info available.
#3 0x06503144 in JavaThread::JavaThread () from
/usr/lib/jvm/java/jre/lib/i386/server/libjvm.so
No symbol table info available.
#4 0x062f006e in attach_current_thread () from
/usr/lib/jvm/java/jre/lib/i386/server/libjvm.so
No symbol table info available.
#5 0x062eee08 in jni_AttachCurrentThread () from
/usr/lib/jvm/java/jre/lib/i386/server/libjvm.so
No symbol table info available.
#6 0xb7f1a4bd in getJNIEnv () at hdfsJniHelper.c:347
vm = (JavaVM *) 0x65ccfcc
vmBuf = 0xb74a0270
env = (JNIEnv *) 0xb7eb73e2
rv = 106745804
noVMs = 1
#7 0xb7f17143 in hdfsConnect (host=0x804aac2 "default", port=0) at
hdfs.c:119
env = (JNIEnv *) 0x0
jConfiguration = (jobject) 0x0
jFS = (jobject) 0x0
jURI = (jobject) 0x0
jURIString = (jstring) 0x0
jVal = {z = 0 '\0', b = 0 '\0', c = 0, s = 0, i = 0, j = 0, f = 0, d =
0, l = 0x0}
cURI = 0x0
gFsRef = (jobject) 0x0
#8 0x0804904b in worker_thread_w (arg=0x1) at hdfsbench.cpp:192
idx = 1
path = {static npos = 4294967295,
_M_dataplus = {<std::allocator<char>> =
{<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>},
_M_p = 0x804e484 "/tmp/test/txt1"}}
fs = (hdfsFS) 0x0
writeFile = (hdfsFile) 0x0
i = 0
bwrite = 0
boffset = 0
tv_start = {tv_sec = 0, tv_usec = 0}
tv_end = {tv_sec = 0, tv_usec = 0}
#9 0xb7f2246b in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
No symbol table info available.
#10 0xb7da06de in clone () from /lib/tls/i686/cmov/libc.so.6


--
Yingyuan Cheng