license: xlators/protocol/server dual license GPLv2 and LGPLv3+

BUG: 951549
Change-Id: I3de5bd86d4238a60a0a85ba2e15d9c131969b210
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>
Reviewed-on: http://review.gluster.org/4816
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>
glusterd: big lock - a coarse-grained locking to prevent races

There are primarily three lists that are part of glusterd process,
that are concurrently accessed. Namely, priv->volumes, priv->peers
and volinfo->bricks_list.

Big-lock approach
-----------------
WHAT IS IT?
Big lock is a coarse-grained lock which protects all three
lists, mentioned above, from racy access.

HOW DOES IT WORK?
At any given point in time, glusterd's thread(s) are in execution
_iff_ there is a preceding, inbound network event. Of course, the
sigwaiter thread and timer thread are exceptions.
A network event is an external trigger to glusterd, via the epoll
thread, in the form of POLLIN and POLLERR.
As long as we take the big-lock at all such entry points and yield
it when we are done, we are guaranteed that all the network events,
accessing the global lists, are serialised.

This amounts to holding the big lock at
- all the handlers of all the actors in glusterd. (POLLIN)
- all the cbks in glusterd. (POLLIN)
- rpc_notify (DISCONNECT event), if we access/modify
  one of the three lists. (POLLERR)

In the case of synctask'ized volume operations, we must remember that,
if we held the big lock for the entire duration of the handler,
we may block other non-synctask rpc actors from executing.
For eg, volume-start would block in PMAP SIGNIN, if done incorrectly.
To prevent this, we need to yield the big lock, when we yield the
synctask, and reacquire on waking up of the synctask.

Change-Id: Ib929f9905b55fb6c3fc27fefb497a26dba058e4f
BUG: 948686
Signed-off-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-on: http://review.gluster.org/4784
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
object-storage: turn off stat() for container list

Turn of stat() system calls used to fetch the file size during a
container listing operation since these system calls can swamp Gluster
and the result is most often not used.

When a GET or HEAD request is made on a container, stat() system calls
are made during the Python standard library method, os.walk, to
determine if a given directory entry is another directory to recurse
into, and then utils._update_list() will stat() each file to get it
size, and finally utils.get_container_details_from_fs() will stat()
each directory encountered.

For most installations we have seen so far, we don't need the
container listing to accurately return the size of all the objects in
the container, so we can reduce the number of stat() system calls by
not fetching the size of the object.

For now, turn it off by default, and provide an /etc/swift/fs.conf
configuration parameter to turn it back on:

  accurate_size_in_listing = yes

The default for the above is "no".

Change-Id: I7dde11e14bb32ecafa3eabb08852f1ffc4366b35
BUG: 903396
Signed-off-by: Mohammed Junaid <junaid@redhat.com>
Reviewed-on: http://review.gluster.org/4787
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Reviewed-by: Anand Avati <avati@redhat.com>
object-storage: cleanup err handling in Glusterfs.

Change-Id: I4fa1a7b9214c6897459a99bedde80e84eb2b9cbc
BUG: 904370
Signed-off-by: Mohammed Junaid <junaid@redhat.com>
Reviewed-on: http://review.gluster.org/4788
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>
object-storage: provide more common cfg defaults

Provide more common configuration defaults, as seen and recommended across
many large customer installations, as well as provide some guidance on how to
set the parameters.

See BZ 904629 (https://bugzilla.redhat.com/show_bug.cgi?id=904629).

Change-Id: Id9f20aafd75f2a0b589c67654dce87534bf80c33
BUG: 904629
Signed-off-by: Mohammed Junaid <junaid@redhat.com>
Reviewed-on: http://review.gluster.org/4789
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>