Commit fdd6efb6 authored by unknown's avatar unknown
Browse files

BUG#24143 Heavy file fragmentation with multiple ndbd on single fs 

If we have the XFS headers (at build time) we can use XFS specific ioctls
(once testing the file is on XFS) to better allocate space.

This dramatically improves performance of mysql-test-run cases as well:

e.g.
number of extents for ndb_dd_basic tablespaces and log files
BEFORE this patch: 57, 13, 212, 95, 17, 113 
WITH this patch  :  ALL 1 or 2 extents

(results are consistent over multiple runs. BEFORE always has several files
with lots of extents).

As for timing of test run:
BEFORE
ndb_dd_basic                   [ pass ]         107727
real    3m2.683s
user    0m1.360s
sys     0m1.192s

AFTER
ndb_dd_basic                   [ pass ]          70060
real    2m30.822s
user    0m1.220s
sys     0m1.404s

(results are again consistent over various runs)

similar for other tests (BEFORE and AFTER):
ndb_dd_alter                   [ pass ]         245360
ndb_dd_alter                   [ pass ]         211632


configure.in:
  Check for XFS headers
storage/ndb/src/kernel/blocks/ndbfs/AsyncFile.cpp:
  If the XFS headers are installed, use the xfsctl(XFS_IOC_RESVSP64) call (a
  wrapper around ioctl) to tell the xfs file system how much space to reserve
  for this file.
parent 42c2a2cb

configure.in

+2 −0
Original line number Diff line number Diff line
@@ -697,6 +697,8 @@ AC_CHECK_HEADERS(fcntl.h float.h floatingpoint.h ieeefp.h limits.h \ 
 sys/ioctl.h malloc.h sys/malloc.h sys/ipc.h sys/shm.h linux/config.h \

 sys/resource.h sys/param.h)



AC_CHECK_HEADERS([xfs/xfs.h])



#--------------------------------------------------------------------

# Check for system libraries. Adds the library to $LIBS

# and defines HAVE_LIBM etc

storage/ndb/src/kernel/blocks/ndbfs/AsyncFile.cpp

+16 −0
Original line number Diff line number Diff line
@@ -18,6 +18,10 @@ 
#include <my_sys.h>

#include <my_pthread.h>



#ifdef HAVE_XFS_XFS_H

#include <xfs/xfs.h>

#endif



#include "AsyncFile.hpp"



#include <ErrorHandlingMacros.hpp>
@@ -459,6 +463,18 @@ void AsyncFile::openReq(Request* request) 
    Uint32 index = 0;

    Uint32 block = refToBlock(request->theUserReference);



#ifdef HAVE_XFS_XFS_H

    if(platform_test_xfs_fd(theFd))

    {

      ndbout_c("Using xfsctl(XFS_IOC_RESVSP64) to allocate disk space");

      xfs_flock64_t fl;

      fl.l_whence= 0;

      fl.l_start= 0;

      fl.l_len= (off64_t)sz;

      if(xfsctl(NULL, theFd, XFS_IOC_RESVSP64, &fl) < 0)

        ndbout_c("failed to optimally allocate disk space");

    }

#endif

#ifdef HAVE_POSIX_FALLOCATE

    posix_fallocate(theFd, 0, sz);

#endif