Bug 1227714 – [RFE] Allow mom to run as standalone process

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Bug 1227714 - [RFE] Allow mom to run as standalone process

Summary:	[RFE] Allow mom to run as standalone process

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise Virtualization Manager
Classification:	Red Hat
Component:	mom (Show other bugs)
Sub Component:
Version:	3.5.3
Hardware:	Unspecified Unspecified

Priority	unspecified Severity unspecified
Target Milestone:	ovirt-3.6.0-rc
Target Release:	3.6.0
Assigned To:	Martin Sivák
QA Contact:	Shira Maximov
Docs Contact:

URL:
Whiteboard:
Keywords:	FutureFeature

Depends On:	1240640
Blocks:
	Show dependency tree / graph

Reported:	2015-06-03 07:16 EDT by Francesco Romani
Modified:	2016-03-09 09:44 EST (History)
CC List:	12 users (show)

See Also:	1182097
Fixed In Version:
Doc Type:	Enhancement
Doc Text:	With this update, MoM has now been separated from VDSM, and runs as a standalone process that communicates with VDSM using XML-RPC over a UNIX socket. This makes it possible to reduce the number of threads that VDSM creates, and results in almost no busy threads in MoM, resolving an issue with the Python global interpreter lock and improving performance on high-end machines such as those with 100 or more CPUs.
Story Points:	---
Clone Of:
Environment:
Last Closed:	2016-03-09 09:44:34 EST
Type:	Bug
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	SLA
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
oVirt gerrit	37294	master	ABANDONED	VDSM interface using JSON-RPC	Never
oVirt gerrit	41570	master	MERGED	New hypervisor interface for remote VDSM over XML-RPC with stats caching	Never
oVirt gerrit	41571	master	MERGED	Add support for KSM and CpuTune calls to XMLRPC for MOM to use	Never
oVirt gerrit	41602	master	MERGED	Separate MOM to an external process	Never
oVirt gerrit	42228	master	MERGED	Allow using unix socket for the RPC port	Never
oVirt gerrit	42353	master	MERGED	Increase MOM intervals between stats and policy evaluation cycles	Never
Red Hat Product Errata	RHBA-2016:0384	normal	SHIPPED_LIVE	mom bug fix and enhancement update	2016-03-09 14:07:42 EST

Groups: None (edit)

Description Francesco Romani 2015-06-03 07:16:21 EDT

MOM runs inside the VDSM process. We want to make it possible to run as standalone process, to the reduce the pressure on the python GIL.
Running MOM separately also make it easier to profile and to evaluate the performances of it, and also of VDSM.

Comment 1 Max Kovgan 2015-06-28 10:12:37 EDT

ovirt-3.6.0-3 release

Comment 2 Shira Maximov 2015-08-24 03:14:10 EDT

martin, please add steps to verify this bug

Comment 3 Roy Golan 2015-08-24 09:22:50 EDT

just to make sure, 3.6 mom installation is still a dependecy of the vdsm rpm or one needs to install mom separately?

Comment 4 Martin Sivák 2015-08-24 10:40:43 EDT

Shira: Just start VDSM and run any of your MOM scenarios (ballooning, ksm, …) + check whether there is a separate process running (using for example ps or systemctl status mom-vdsm).

Roy: VDSM still depends on mom via RPM dependency.

Comment 5 Shira Maximov 2015-08-25 05:11:25 EDT

Verified on : 
3.6.0-0.12.master.el6
vdsm-4.17.3-1.el7ev.noarch
vdsm-4.17.3-1.el7ev.noarch

i run the regular tests and check that the mom service is running :

[root@dhcp160-245 ~]# systemctl status mom-vdsm
● mom-vdsm.service - MOM instance configured for VDSM purposes
   Loaded: loaded (/usr/lib/systemd/system/mom-vdsm.service; disabled; vendor preset: enabled)
   Active: active (running) since Tue 2015-08-25 10:42:24 IDT; 14min ago
 Main PID: 9652 (python)
   CGroup: /system.slice/mom-vdsm.service
           └─9652 python /usr/sbin/momd -c /etc/vdsm/mom.conf

Comment 8 errata-xmlrpc 2016-03-09 09:44:34 EST

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-0384.html

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