You're welcome. Have fun with hadoop! Regards, Leo
From: Jun Li [mailto:jltz922...@gmail.com] Sent: Sunday, June 23, 2013 11:24 PM To: user@hadoop.apache.org Subject: Re: how to turn on NativeIO.posixFadviseIfPossible Hi Leo, Following your instruction on moving the sections in configure.ac<http://configure.ac>, I am able to re-compile the code base and I can find that the "objdump" returns the correct fadvise symbols as you described in your earlier email. I then ran the TestNativeIO.java class and I believe that the Fadvise test case gets passed now. Thank you very much for the help! Regards, Jun On Sat, Jun 22, 2013 at 4:42 PM, Leo Leung <lle...@ddn.com<mailto:lle...@ddn.com>> wrote: Hi Jun, Try moving the section between: dnl Check for headers needed by the native Group.... [...include everything in between inclusive ...] AC_FUNC_STRERROR_R to higher place (insert before) # Checks for libraries. dnl Check for '-ldl' Hope this helps :) From: Jun Li [mailto:jltz922...@gmail.com<mailto:jltz922...@gmail.com>] Sent: Saturday, June 22, 2013 3:26 AM To: user@hadoop.apache.org<mailto:user@hadoop.apache.org> Subject: Re: how to turn on NativeIO.posixFadviseIfPossible Hi Leo, Thanks for the detailed instruction. I started from the clean downloaded hadoop1.1.12 copy and then I issue the command: ant -Dcompile.native=true. And with the configure.ac<http://configure.ac> that comes with the downloaded package, without any changes, the following is the compilation output: [exec] checking fcntl.h usability... yes [exec] checking fcntl.h presence... yes [exec] checking for fcntl.h... yes [exec] checking for stdlib.h... (cached) yes [exec] checking for string.h... (cached) yes [exec] checking for unistd.h... (cached) yes [exec] checking for fcntl.h... (cached) yes [exec] checking for posix_fadvise... no [exec] checking for fcntl.h... (cached) yes [exec] checking for sync_file_range... no [exec] checking for an ANSI C-conforming const... yes [exec] checking for memset... no [exec] checking whether strerror_r is declared... yes [exec] checking for strerror_r... no I have difficulty to follow the "+" and "-" relate patching sequence that you stated in your email earlier. I have attached the "configure.ac<http://configure.ac>" file that I copied out of the hadoop1.1.12/src/native directory. Could you help me to construct the configure.ac<http://configure.ac> with the correct patching that you described, using the one that I attached in this email, and send back to me? Then I will use the patched one to build the native library. Regards, Jun On Fri, Jun 21, 2013 at 12:35 PM, Leo Leung <lle...@ddn.com<mailto:lle...@ddn.com>> wrote: Hi Jun: Looks like it is not in the apache hadoop 1.x release binaries, this probably will have to be answered by the apache hadoop 1.x release team To build the native libs: 1) Get the source code and install the dependencies to compile hadoop 2) You'll have to setup the env for it, such as JAVA_HOME. Gcc installed etc. 3) Got to <hadoop-source dir> ant [veryclean] compile-core-native >compile.out Verify with [branch-1]$ objdump -Tt ./build/native/Linux-amd64-64/lib/libhadoop.so | grep fadv 00000000000056a0 g F .text 00000000000000a3 Java_org_apache_hadoop_io_nativeio_NativeIO_posix_1fadvise 0000000000000000 F *UND* 0000000000000000 posix_fadvise@@GLIBC_2.2.5 0000000000000000 DF *UND* 0000000000000000 GLIBC_2.2.5 posix_fadvise 00000000000056a0 g DF .text 00000000000000a3 Base Java_org_apache_hadoop_io_nativeio_NativeIO_posix_1fadvise If you get an error about "make distclean" error Just cd in src/native and run make distclean (to cleanup ) Example of ant output that shows checking for fadvise [exec] checking for fcntl.h... yes [exec] checking for stdlib.h... (cached) yes [exec] checking for string.h... (cached) yes [exec] checking for unistd.h... (cached) yes [exec] checking for fcntl.h... (cached) yes [exec] checking for posix_fadvise... yes [exec] checking for fcntl.h... (cached) yes [exec] checking for sync_file_range... yes If you see "no" for posix_fadvise or "sync_file_range" And you are sure you have posix_fdavise support (RHEL 6.x or CentOS 6.x) you may need to move the section on src/native/configure.ac<http://configure.ac> Try to modify the configure.ac<http://configure.ac> --- src/native/configure.ac<http://configure.ac> (revision 1495498) +++ src/native/configure.ac<http://configure.ac> (working copy) @@ -47,6 +47,21 @@ AC_PROG_CC AC_PROG_LIBTOOL +dnl check for posix_fadvise +AC_CHECK_HEADERS(fcntl.h, [AC_CHECK_FUNCS(posix_fadvise)]) + +dnl check for sync_file_range +AC_CHECK_HEADERS(fcntl.h, [AC_CHECK_FUNCS(sync_file_range)]) + +# Checks for typedefs, structures, and compiler characteristics. +AC_C_CONST + +# Checks for library functions. +AC_CHECK_FUNCS([memset]) + +# Check for nonstandard STRERROR_R +AC_FUNC_STRERROR_R + # Checks for libraries. dnl Check for '-ldl' AC_CHECK_LIB([dl], [dlopen]) @@ -104,21 +119,6 @@ dnl Check for headers needed by the native Group resolution implementation AC_CHECK_HEADERS([fcntl.h stdlib.h string.h unistd.h], [], AC_MSG_ERROR(Some system headers not found... please ensure their presence on your platform.)) -dnl check for posix_fadvise -AC_CHECK_HEADERS(fcntl.h, [AC_CHECK_FUNCS(posix_fadvise)]) - -dnl check for sync_file_range -AC_CHECK_HEADERS(fcntl.h, [AC_CHECK_FUNCS(sync_file_range)]) - -# Checks for typedefs, structures, and compiler characteristics. -AC_C_CONST - -# Checks for library functions. -AC_CHECK_FUNCS([memset]) - -# Check for nonstandard STRERROR_R -AC_FUNC_STRERROR_R - AC_CONFIG_FILES([Makefile]) AC_OUTPUT Hope this helps From: Jun Li [mailto:jltz922...@gmail.com<mailto:jltz922...@gmail.com>] Sent: Friday, June 21, 2013 9:44 AM To: user@hadoop.apache.org<mailto:user@hadoop.apache.org> Subject: Re: how to turn on NativeIO.posixFadviseIfPossible Hi Leo, Following your instruction, the following is what I got: [junli@mercoop-26 Linux-amd64-64]$ objdump -Tt libhadoop.so | grep -I fadvise 0000000000004d70 g F .text 000000000000006f Java_org_apache_hadoop_io_nativeio_NativeIO_posix_1fadvise 0000000000004d70 g DF .text 000000000000006f Base Java_org_apache_hadoop_io_nativeio_NativeIO_posix_1fadvise Apparently the part of "the GLIBC" is not there The libhadoop.so is the one that I downloaded as part of the tar.gz of hadoop.1.1.2 from the Hadoop Apache web site. Could you let me know how I can use the source code directory in the downloaded Hadoop Apache package, to re-compile the libhadoop.so and to make sure that the fadvise call is able to get referenced? Regards, Jun On Fri, Jun 21, 2013 at 9:19 AM, Leo Leung <lle...@ddn.com<mailto:lle...@ddn.com>> wrote: This looks like a compilation problem on the native hadoop libraries. Please locate the libhadoop.so library on your system and run [shell] objdump -Tt libhadoop.so | grep -I fadvise If you don't see something like the following *the GLIBC* part (that means the system where the share lib was compiled did not have it) 00000000000056a0 g F .text 00000000000000a3 Java_org_apache_hadoop_io_nativeio_NativeIO_posix_1fadvise 0000000000000000 F *UND* 0000000000000000 posix_fadvise@@GLIBC_2.2.5 0000000000000000 DF *UND* 0000000000000000 GLIBC_2.2.5 posix_fadvise 00000000000056a0 g DF .text 00000000000000a3 Base Java_org_apache_hadoop_io_nativeio_NativeIO_posix_1fadvise Note: objdump is from binutils- rpm (you can use yum install to install it if you don't have it) -----Original Message----- From: Jun Li [mailto:jltz922...@gmail.com<mailto:jltz922...@gmail.com>] Sent: Friday, June 21, 2013 1:35 AM To: user@hadoop.apache.org<mailto:user@hadoop.apache.org> Subject: how to turn on NativeIO.posixFadviseIfPossible Hi, I downloaded the current stable version from the Apache Hadoop web site, hadoop-1.1.2. My machine is an AMD-based machine and Redhat Enterprise 6.1. The detailed Linux kernel version is: 2.6.32-131.0.15.el6.x86_64 I ran the TestNativeIO.java under the distribution directory of "test/org/apache/hadoop/io/nativeio/TestNativeIO.java" and tried to understand how NativeIO.posixFadviseIfPossible behaves, in particular, to check whether "posix_fadvise" is turned on or not. I am interested in this call as it is used in Read-Ahead-Pool to cache data to the OS's buffer cache. The following is the test case that I ran: @Test public void testPosixFadvise() throws Exception { FileInputStream fis = new FileInputStream("/dev/zero"); try { NativeIO.posixFadviseIfPossible(fis.getFD(), 0, 0, NativeIO.POSIX_FADV_SEQUENTIAL); } catch (NativeIOException noe) { // we should just skip the unit test on machines where we don't // have fadvise support assumeTrue(false); } finally { fis.close(); } However, when I stepped into the code and reached "NativeIO.java" under the package of "org.apache.hadoop.io.nativeio", in the particular call below: public static void posixFadviseIfPossible( FileDescriptor fd, long offset, long len, int flags) throws NativeIOException { if (nativeLoaded && fadvisePossible) { try { posix_fadvise(fd, offset, len, flags); } catch (UnsupportedOperationException uoe) { fadvisePossible = false; } catch (UnsatisfiedLinkError ule) { fadvisePossible = false; } } } The call to "posix_fadvise" threw the "UnsupportedOperationException" exception. I further traced to the native library, and in the code "NativeIO.c", I found JNIEXPORT void JNICALL Java_org_apache_hadoop_io_nativeio_NativeIO_posix_1fadvise( JNIEnv *env, jclass clazz, jobject fd_object, jlong offset, jlong len, jint flags) { #ifndef HAVE_POSIX_FADVISE THROW(env, "java/lang/UnsupportedOperationException", "fadvise support not available"); #else ... } I believe that the problem of throwing the exception is because "HAVE_POSIX_FADVISE" is not defined. I made sure that the native IO library is loaded properly in the Java code, as I can successfully run the other test cases in "TestNativeIO.java". So my question is: should I re-compile the "libhadoop" in order to get the version of the shared library that can have "HAVE_POSIX_FADVISE" turned on? Or by default, FADVISE is turned on already? Thank you!
