glusterfs.git/xlators/cluster/afr/src/afr.c, branch v3.12.13

cluster/afr: remove unnecessary child_up initialization

2018-02-06T07:07:33+00:00

The child_up array was initialized with all elements being -1 to
allow afr_notify() to differentiate down bricks from bricks that
haven't reported yet. With current implementation this is not needed
anymore and it was causing unexpected results when other parts of
the code considered that if child_up[i] != 0, it meant that it was up.

Backport of:
> BUG: 1541038

Change-Id: I2a9d712ee64c512f24bd5cd3a48dcb37e3139472
BUG: 1541930
Signed-off-by: Xavier Hernandez

cluster/afr: Make choose-local "reconfigurable"

2017-10-12T18:46:10+00:00

        Backport of:
        > Change-Id: Ibab292ba705d993b475cd0303fb3318211fb2500
        > Reviewed-on: https://review.gluster.org/18026
        > BUG: 1480525
        > cherry-picked from commit 1e2d6537875d16b783e3c50ada7ee61487c6d796

With this change, enabling choose-local (which means its state makes
transition from "off" to "on") will be effective after the first
gfid-lookup on "/" since volume-set was executed.

Change-Id: Ibab292ba705d993b475cd0303fb3318211fb2500
BUG: 1501022
Signed-off-by: Krutika Dhananjay

cluster/afr: Remove debug logs in fix_quorum_options()

2017-05-19T01:37:21+00:00

Change-Id: Id019b0c6425849eece8a9aba7acec9a521dfb10b
BUG: 1452378
Signed-off-by: Vijay Bellur 
Reviewed-on: https://review.gluster.org/17335
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Jeff Darcy 
CentOS-regression: Gluster Build System

Halo Replication feature for AFR translator

2017-05-02T10:23:53+00:00

Summary:
Halo Geo-replication is a feature which allows Gluster or NFS clients to write
locally to their region (as defined by a latency "halo" or threshold if you
like), and have their writes asynchronously propagate from their origin to the
rest of the cluster.  Clients can also write synchronously to the cluster
simply by specifying a halo-latency which is very large (e.g. 10seconds) which
will include all bricks.

In other words, it allows clients to decide at mount time if they desire
synchronous or asynchronous IO into a cluster and the cluster can support both
of these modes to any number of clients simultaneously.

There are a few new volume options due to this feature:
  halo-shd-latency:  The threshold below which self-heal daemons will
  consider children (bricks) connected.

  halo-nfsd-latency: The threshold below which NFS daemons will consider
  children (bricks) connected.

  halo-latency: The threshold below which all other clients will
  consider children (bricks) connected.

  halo-min-replicas: The minimum number of replicas which are to
  be enforced regardless of latency specified in the above 3 options.
  If the number of children falls below this threshold the next
  best (chosen by latency) shall be swapped in.

New FUSE mount options:
  halo-latency & halo-min-replicas: As descripted above.

This feature combined with multi-threaded SHD support (D1271745) results in
some pretty cool geo-replication possibilities.

Operational Notes:
- Global consistency is gaurenteed for synchronous clients, this is provided by
  the existing entry-locking mechanism.
- Asynchronous clients on the other hand and merely consistent to their region.
  Writes & deletes will be protected via entry-locks as usual preventing
  concurrent writes into files which are undergoing replication.  Read operations
  on the other hand should never block.
- Writes are allowed from _any_ region and propagated from the origin to all
  other regions.  The take away from this is care should be taken to ensure
  multiple writers do not write the same files resulting in a gfid split-brain
  which will require resolution via split-brain policies (majority, mtime &
  size).  Recommended method for preventing this is using the nfs-auth feature to
  define which region for each share has RW permissions, tiers not in the origin
  region should have RO perms.

TODO:
- Synchronous clients (including the SHD) should choose clients from their own
  region as preferred sources for reads.  Most of the plumbing is in place for
  this via the child_latency array.
- Better GFID split brain handling & better dent type split brain handling
  (i.e. create a trash can and move the offending files into it).
- Tagging in addition to latency as a means of defining which children you wish
  to synchronously write to

Test Plan:
- The usual suspects, clang, gcc w/ address sanitizer & valgrind
- Prove tests

Reviewers: jackl, dph, cjh, meyering

Reviewed By: meyering

Subscribers: ethanr

Differential Revision: https://phabricator.fb.com/D1272053

Tasks: 4117827

Change-Id: I694a9ab429722da538da171ec528406e77b5e6d1
BUG: 1428061
Signed-off-by: Kevin Vigor 
Reviewed-on: http://review.gluster.org/16099
Reviewed-on: https://review.gluster.org/16177
Tested-by: Pranith Kumar Karampuri 
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Pranith Kumar Karampuri

core: run many bricks within one glusterfsd process

2017-01-31T00:13:58+00:00

This patch adds support for multiple brick translator stacks running
in a single brick server process.  This reduces our per-brick memory usage by
approximately 3x, and our appetite for TCP ports even more.  It also creates
potential to avoid process/thread thrashing, and to improve QoS by scheduling
more carefully across the bricks, but realizing that potential will require
further work.

Multiplexing is controlled by the "cluster.brick-multiplex" global option.  By
default it's off, and bricks are started in separate processes as before.  If
multiplexing is enabled, then *compatible* bricks (mostly those with the same
transport options) will be started in the same process.

Change-Id: I45059454e51d6f4cbb29a4953359c09a408695cb
BUG: 1385758
Signed-off-by: Jeff Darcy 
Reviewed-on: https://review.gluster.org/14763
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Vijay Bellur

afr: fix auto-quorum

2016-11-29T06:41:24+00:00

(1) afr_have_quorum is dead code.  It was copied to afr_has_quorum,
and everything else uses that, but the original was never deleted
(until now).

(2) Auto-quorum should be default for any N>2.  Leaving quorum
disabled is BAD, but apparently deemed acceptable for N=2 because
there's no real quorum in that case.  For any larger number (including
arbiter configurations) there is such a thing as real quorum and we
should use it by default.  Note that for N=3 the answers we get from
"N % 2" (the old check) and "N > 2" (the new one) are the same.

(3) The special case for even N in afr_has_quorum has been simplified and
explained more thoroughly in a comment.

Change-Id: I48b33c15093512fecf516b26dcf09afecb7ae33b
Signed-off-by: Jeff Darcy 
Reviewed-on: http://review.gluster.org/15873
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Vijay Bellur 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Pranith Kumar Karampuri

afr: Implement IPC fop

2016-09-29T18:22:04+00:00

Currently ipc() is not implemented in afr. md-cache and upcall
uses ipc to register the list of xattrs, [1] for more details.
For the ipc op GF_IPC_TARGET_UPCALL, it has to be wound to all
the replica subvolumes. ipc() is failed when any of the
subvolumes fails with other than ENOTCONN or all of the subvolumes
are down.

[1] http://review.gluster.org/#/c/15002/

Change-Id: I0f651330eafda64e4d922043fe53bd0014536247
BUG: 1211863
Signed-off-by: Poornima G 
Reviewed-on: http://review.gluster.org/15378
Tested-by: Pranith Kumar Karampuri 
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Pranith Kumar Karampuri

afr: Consume compound fops in afr transaction

2016-09-01T17:22:39+00:00

Change-Id: Ib06ece3cce1b10d28d6d2953da28444f5c2457ad
BUG: 1290304
Signed-off-by: Anuradha Talur 
Reviewed-on: http://review.gluster.org/15014
Tested-by: Pranith Kumar Karampuri 
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Krutika Dhananjay 
Reviewed-by: Pranith Kumar Karampuri

cluster/ec: Do multi-threaded self-heal

2016-08-24T22:24:22+00:00

BUG: 1368451
Change-Id: I5d6b91d714ad6906dc478a401e614115c89a8fbb
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/15083
Smoke: Gluster Build System 
Reviewed-by: Ashish Pandey 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

cluster/afr: Give option to do consistent-io

2016-08-22T20:55:42+00:00

Problem:
When tiering/rebalance does migrations and afr with 2-way replica is in
picture, migration can read stale data if the source brick goes down and writes
to the destination. After this deletion of the file leads to permanent loss of
data after migration.

Fix:
Rebalance/tiering should migrate only when the data is definitely not stale. So
introduce an option in afr called consistent-io which will be enabled in
migration daemons.

BUG: 1306398
Change-Id: I750f65091cc70a3ed4bf3c12f83d0949af43920a
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/13425
Reviewed-by: Anuradha Talur 
Reviewed-by: Krutika Dhananjay 
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System