diff options
author | Csaba Henk <csaba@redhat.com> | 2012-05-22 16:08:48 +0530 |
---|---|---|
committer | Vijay Bellur <vijay@gluster.com> | 2012-06-13 08:39:06 -0700 |
commit | 8a4c0b911c7bce4fd0fbab0cc23a59dcca93a5d3 (patch) | |
tree | cfff733dad94671ff2efcce9f430c2d713766628 /xlators/features/marker/utils/syncdaemon/gsyncd.py | |
parent | 118ce698e8af425bf75ceab2c9e71cfdaa0ac848 (diff) |
gsyncd / geo-rep : failover/failback
This commit is based on Venky Shankar <vshankar@>'s
original implementation. Let us first quote Venky's
description, then we summarize changes to his work.
------
First version of failover/failback.
Failback mechanism uses two exclusive modes:
* blind-sync
This mode works with xtime pairs (both master and slave) to
identify candidated to sync the original master from the slave
* wrapup-sync
This mode is similar to the normal working of gsyncd except
that orphaned entities in the gluster volume are not assigned
xtimes. This prevents un-necessary transfer of data for such
entities.
Modes can be enabled via:
gluster volume geo-replication M S config special_sync_mode blind
gluster volume geo-replication M S config special_sync_mode wrapup
To turn off the special modes (i.e. to revert to normal gsyncd behaviour) use:
gluster volume geo-replication colon-d0 192.168.1.2::colon-d config \!special_sync_mode
------
Code has been refactored to meet following goals:
- make checkpointing work with special sync modes
- move out sync mode related conditionals from the crawl
loop and make all decisions to be made at startup
time
- be intrusive to the crawl loop to smallest possible degree
(we will have to change/revisit it for other reasons,
and the complexity of that should not increase)
So, xtime parsing/updating/evaluation that's specific to
the certain special modes are represented as mixin classes;
basic operation logic is in an abstract base class.
On startup, special-sync-mode tunable is dynamically dispatched
to the corresponding mixin and the actual master class is
derived from the chosen mixin and the ABS.
Change-Id: Ic9b8448f31ad4239a8200dc689f7d713662a67de
BUG: 830497
Signed-off-by: Csaba Henk <csaba@redhat.com>
Reviewed-on: http://review.gluster.com/3541
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Diffstat (limited to 'xlators/features/marker/utils/syncdaemon/gsyncd.py')
-rw-r--r-- | xlators/features/marker/utils/syncdaemon/gsyncd.py | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/xlators/features/marker/utils/syncdaemon/gsyncd.py b/xlators/features/marker/utils/syncdaemon/gsyncd.py index d68cea672..165aebda1 100644 --- a/xlators/features/marker/utils/syncdaemon/gsyncd.py +++ b/xlators/features/marker/utils/syncdaemon/gsyncd.py @@ -172,6 +172,14 @@ def main_i(): op.add_option('--allow-network', metavar='IPS', default='') op.add_option('--state-socket-unencoded', metavar='SOCKF', type=str, action='callback', callback=store_abs) op.add_option('--checkpoint', metavar='LABEL', default='') + # tunables for failover/failback mechanism: + # None - gsyncd behaves as normal + # blind - gsyncd works with xtime pairs to identify + # candidates for synchronization + # wrapup - same as normal mode but does not assign + # xtimes to orphaned files + # see crawl() for usage of the above tunables + op.add_option('--special-sync-mode', type=str, help=SUPPRESS_HELP) op.add_option('-c', '--config-file', metavar='CONF', type=str, action='callback', callback=store_local) # duh. need to specify dest or value will be mapped to None :S |