diff options
author | Venky Shankar <vshankar@redhat.com> | 2014-02-19 20:47:46 +0530 |
---|---|---|
committer | Venky Shankar <vshankar@redhat.com> | 2014-05-14 05:10:15 -0700 |
commit | d2db585ce7e26851178104433fa9422482d8719e (patch) | |
tree | 2e52f15cf261906debd8ec54106ffe9f84af881e /xlators/features/changelog/lib/examples | |
parent | bfde478cedda8267134ee3807c8db5e042115eae (diff) |
features/changelog : historical journal consumption.
Facilitates Glusterfs with the ability to detect file-operations
happened in past by scanning the back-end(brick-level) glusterfs
journal (changelog).
Design:
* List of changelogs produces in one perfectly running session are
stored in htime file which also holds necessary information about
the session start and end time.
* Involves fixed sized seeks to identify N'th changelog in the list.
* Requires O(log n), (where n is number of changelogs in the list),
time to identify the end changelog for the given start-end time
interval.
Currently the background processing of changelogs is sub optimal. BZ
1097041 tracks the development effort.
For complete design, refer the below link:
http://lists.nongnu.org/archive/html/gluster-devel/2014-02/msg00206.html
Change-Id: I27e49f75e492e843084d0ecaf9130224d08462a0
BUG: 1091961
Signed-off-by: Ajeet Jha <ajha@redhat.com>
Signed-off-by: Venky Shankar <vshankar@redhat.com>
Signed-off-by: Ajeet Jha <ajha@redhat.com>
Reviewed-on: http://review.gluster.org/6930
Reviewed-by: Kotresh HR <khiremat@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Diffstat (limited to 'xlators/features/changelog/lib/examples')
-rw-r--r-- | xlators/features/changelog/lib/examples/c/get-history.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/xlators/features/changelog/lib/examples/c/get-history.c b/xlators/features/changelog/lib/examples/c/get-history.c new file mode 100644 index 00000000000..33eb8c32d4d --- /dev/null +++ b/xlators/features/changelog/lib/examples/c/get-history.c @@ -0,0 +1,109 @@ +/* + Copyright (c) 2013 Red Hat, Inc. <http://www.redhat.com> + This file is part of GlusterFS. + + This file is licensed to you under your choice of the GNU Lesser + General Public License, version 3 or any later version (LGPLv3 or + later), or the GNU General Public License, version 2 (GPLv2), in all + cases as published by the Free Software Foundation. +*/ + +/** + * get set of new changes every 10 seconds (just print the file names) + * + * Compile it using: + * gcc -o gethistory `pkg-config --cflags libgfchangelog` get-history.c \ + * `pkg-config --libs libgfchangelog` + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <sys/un.h> +#include <limits.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <errno.h> + +#include "changelog.h" + +#define handle_error(fn) \ + printf ("%s (reason: %s)\n", fn, strerror (errno)) + +int +main (int argc, char ** argv) +{ + int i = 0; + int ret = 0; + ssize_t nr_changes = 0; + ssize_t changes = 0; + char fbuf[PATH_MAX] = {0,}; + unsigned long end_ts = 0; + + ret = gf_changelog_register ("/export1/v1/b1", + "/tmp/scratch_v1", "/tmp/scratch_v1/changes.log", + 9, 5); + if (ret) { + handle_error ("register failed"); + goto out; + } + + int a, b; + printf ("give the two numbers start and end\t"); + scanf ("%d%d", &a, &b); + ret = gf_history_changelog ("/export1/v1/b1/.glusterfs/changelogs",a, b, 3, &end_ts); + if (ret == -1) { + printf ("history failed"); + goto out; + } + + printf ("end time till when changelog available : %d , ret(%d) \t", end_ts, ret); + fflush(stdout); + + while (1) { + nr_changes = gf_history_changelog_scan (); + printf ("scanned, nr_changes : %d\n",nr_changes); + if (nr_changes < 0) { + handle_error ("scan(): "); + break; + } + + if (nr_changes == 0) { + printf ("done scanning \n"); + goto out; + } + + printf ("Got %ld changelog files\n", nr_changes); + + while ( (changes = + gf_history_changelog_next_change (fbuf, PATH_MAX)) > 0) { + printf ("changelog file [%d]: %s\n", ++i, fbuf); + + /* process changelog */ + /* ... */ + /* ... */ + /* ... */ + /* done processing */ + + ret = gf_history_changelog_done (fbuf); + if (ret) + handle_error ("gf_changelog_done"); + } + /* + if (changes == -1) + handle_error ("gf_changelog_next_change"); + if (nr_changes ==1){ + printf("continue scanning\n"); + } + + if(nr_changes == 0){ + printf("done scanning \n"); + goto out; + } + */ + } + + +out: + return ret; +} |