From 4737584fffcd25dbe35d17b076c95bf90a422cf2 Mon Sep 17 00:00:00 2001 From: Venky Shankar Date: Tue, 3 Feb 2015 19:22:16 +0530 Subject: features/changelog: RPC'fy {libgf}changelog This patch introduces RPC based communication between the changelog translator and libgfchangelog. It replaces the old pathetic stream based interaction that existed earlier (due to time constraints :-/). Changelog, upon initialization starts a RPC server (rpcsvc) allowing clients to invoke a probe API as a bootup mechanism to request for event notifications. During probe, clients can choose an event filter specifying the type(s) of events they are interested in. As of now there is no way to change the event notification set once the probe RPC call is made, but that is easier to implement. The actual event notifications is done on a separate RPC session. The client (libgfchangelog) itself starts and RPC server which the changelog translator "connects back" during probe. Notifications are dispatched by a bunch of threads from the server (translator) and the client optionally orders them if ordered notifications are requried. FOPs fill in their respective event details in a buffer (rot-buffs to be particular) and a bunch of threads (consumers) swap the buffers out of roatation and dispatch them via RPC. To avoid writer starvation, then number of dispatcher threads is one less than the number of buffer list in rot-buffs.x libgfchangelog becomes purely callback based -- upon event notification from the server (and re-ordering them if required) invoke a callback routine specified by consumer(s). A major part of the patch is also aimed at providing backward compatibility for geo-replication, which was one of the main consumer of the stream based API. Also, this patch does not\ "turn on" event notifications for all fops, just a bunch which is currently in requirement. Another pain point is that the server does not filter events before dispatching it to the clients. That load is taken up by the client itself (although it's done at the library layer rather than making it hard on the callback implementor). This needs improvement and care needs to be taken to not load the server up with expensive filtering mechanisms. Change-Id: Ibf60a432b68f2dfa60c6f9add2bcfd37a9c41395 BUG: 1170075 Signed-off-by: Venky Shankar Reviewed-on: http://review.gluster.org/9708 Reviewed-by: Jeff Darcy Tested-by: Gluster Build System Reviewed-by: Vijay Bellur --- .../features/changelog/lib/src/gf-changelog-rpc.h | 26 ++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 xlators/features/changelog/lib/src/gf-changelog-rpc.h (limited to 'xlators/features/changelog/lib/src/gf-changelog-rpc.h') diff --git a/xlators/features/changelog/lib/src/gf-changelog-rpc.h b/xlators/features/changelog/lib/src/gf-changelog-rpc.h new file mode 100644 index 00000000000..1c982eef809 --- /dev/null +++ b/xlators/features/changelog/lib/src/gf-changelog-rpc.h @@ -0,0 +1,26 @@ +/* + Copyright (c) 2013 Red Hat, Inc. + 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. +*/ + +#ifndef __GF_CHANGELOG_RPC_H +#define __GF_CHANGELOG_RPC_H + +#include "xlator.h" + +#include "gf-changelog-helpers.h" +#include "changelog-rpc-common.h" + +struct rpc_clnt *gf_changelog_rpc_init (xlator_t *, gf_changelog_t *); + +int gf_changelog_invoke_rpc (xlator_t *, gf_changelog_t *, int); + +rpcsvc_t * +gf_changelog_reborp_init_rpc_listner (xlator_t *, char *, char *, void *); + +#endif -- cgit