Re: [ovirt-devel] Question/thoughts about our engine logging framework

From: "Alon Bar-Lev" <alonbl(a)redhat.com&gt; To: "Martin Perina" <mperina(a)redhat.com&gt; Cc: devel(a)ovirt.org Sent: Monday, June 16, 2014 3:26:00 PM Subject: Re: [ovirt-devel] Question/thoughts about our engine logging framework ----- Original Message ----- > From: "Martin Perina" <mperina(a)redhat.com&gt; > To: "Alon Bar-Lev" <alonbl(a)redhat.com&gt; > Cc: devel(a)ovirt.org > Sent: Monday, June 16, 2014 4:22:16 PM > Subject: Re: [ovirt-devel] Question/thoughts about our engine logging > framework > > > > ----- Original Message ----- > > From: "Alon Bar-Lev" <alonbl(a)redhat.com&gt; > > To: "Martin Perina" <mperina(a)redhat.com&gt; > > Cc: devel(a)ovirt.org, "Greg Sheremeta" <gshereme(a)redhat.com&gt; > > Sent: Sunday, June 15, 2014 7:44:22 PM > > Subject: Re: [ovirt-devel] Question/thoughts about our engine logging > > framework > > > > > > > > ----- Original Message ----- > > > From: "Martin Perina" <mperina(a)redhat.com&gt; > > > To: "Alon Bar-Lev" <alonbl(a)redhat.com&gt; > > > Cc: devel(a)ovirt.org, "Greg Sheremeta" <gshereme(a)redhat.com&gt; > > > Sent: Sunday, June 15, 2014 8:17:13 PM > > > Subject: Re: [ovirt-devel] Question/thoughts about our engine logging > > > framework > > > > > > > > > > > > ----- Original Message ----- > > > > From: "Alon Bar-Lev" <alonbl(a)redhat.com&gt; > > > > To: "Martin Perina" <mperina(a)redhat.com&gt; > > > > Cc: devel(a)ovirt.org, "Greg Sheremeta" <gshereme(a)redhat.com&gt; > > > > Sent: Sunday, June 15, 2014 6:27:09 PM > > > > Subject: Re: [ovirt-devel] Question/thoughts about our engine logging > > > > framework > > > > > > > > > > > > > > > > ----- Original Message ----- > > > > > From: "Martin Perina" <mperina(a)redhat.com&gt; > > > > > To: "Alon Bar-Lev" <alonbl(a)redhat.com&gt; > > > > > Cc: devel(a)ovirt.org, "Greg Sheremeta" <gshereme(a)redhat.com&gt; > > > > > Sent: Sunday, June 15, 2014 7:19:15 PM > > > > > Subject: Re: [ovirt-devel] Question/thoughts about our engine > > > > > logging > > > > > framework > > > > > > > > > > > > > > > > > > > > ----- Original Message ----- > > > > > > From: "Alon Bar-Lev" <alonbl(a)redhat.com&gt; > > > > > > To: "Martin Perina" <mperina(a)redhat.com&gt; > > > > > > Cc: "Greg Sheremeta" <gshereme(a)redhat.com&gt;, devel(a)ovirt.org > > > > > > Sent: Sunday, June 15, 2014 5:07:28 PM > > > > > > Subject: Re: [ovirt-devel] Question/thoughts about our engine > > > > > > logging > > > > > > framework > > > > > > > > > > > > > > > > > > > > > > > > ----- Original Message ----- > > > > > > > From: "Martin Perina" <mperina(a)redhat.com&gt; > > > > > > > To: "Greg Sheremeta" <gshereme(a)redhat.com&gt; > > > > > > > Cc: devel(a)ovirt.org > > > > > > > Sent: Sunday, June 15, 2014 5:34:51 PM > > > > > > > Subject: Re: [ovirt-devel] Question/thoughts about our engine > > > > > > > logging > > > > > > > framework > > > > > > > > > > > > > > > > > > > > > > > > > > > > ----- Original Message ----- > > > > > > > > From: "Greg Sheremeta" <gshereme(a)redhat.com&gt; > > > > > > > > To: "Yair Zaslavsky" <yzaslavs(a)redhat.com&gt; > > > > > > > > Cc: devel(a)ovirt.org > > > > > > > > Sent: Sunday, June 15, 2014 4:25:54 PM > > > > > > > > Subject: Re: [ovirt-devel] Question/thoughts about our engine > > > > > > > > logging > > > > > > > > framework > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ----- Original Message ----- > > > > > > > > > From: "Eli Mesika" <emesika(a)redhat.com&gt; > > > > > > > > > To: "Yair Zaslavsky" <yzaslavs(a)redhat.com&gt; > > > > > > > > > Cc: devel(a)ovirt.org > > > > > > > > > Sent: Sunday, June 15, 2014 10:02:15 AM > > > > > > > > > Subject: Re: [ovirt-devel] Question/thoughts about our > > > > > > > > > engine > > > > > > > > > logging > > > > > > > > > framework > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ----- Original Message ----- > > > > > > > > > > From: "Vojtech Szocs" <vszocs(a)redhat.com&gt; > > > > > > > > > > To: "Martin Perina" <mperina(a)redhat.com&gt; > > > > > > > > > > Cc: devel(a)ovirt.org > > > > > > > > > > Sent: Friday, June 13, 2014 12:57:49 PM > > > > > > > > > > Subject: Re: [ovirt-devel] Question/thoughts about our > > > > > > > > > > engine > > > > > > > > > > logging > > > > > > > > > > framework > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ----- Original Message ----- > > > > > > > > > > > From: "Martin Perina" <mperina(a)redhat.com&gt; > > > > > > > > > > > To: "Yair Zaslavsky" <yzaslavs(a)redhat.com&gt; > > > > > > > > > > > Cc: devel(a)ovirt.org > > > > > > > > > > > Sent: Friday, June 13, 2014 10:43:59 AM > > > > > > > > > > > Subject: Re: [ovirt-devel] Question/thoughts about our > > > > > > > > > > > engine > > > > > > > > > > > logging > > > > > > > > > > > framework > > > > > > > > > > > > > > > > > > > > > > Hi Yair, > > > > > > > > > > > > > > > > > > > > > > I had in my mind to clean up logging framework mess for > > > > > > > > > > > quite > > > > > > > > > > > some > > > > > > > > > > > time > > > > > > > > > > > :-) > > > > > > > > > > > Currently this is the usage of logging frameworks in > > > > > > > > > > > engine > > > > > > > > > > > classes: > > > > > > > > > > > > > > > > > > > > > > java.util.logging.Logger 6.8% > > > > > > > > > > > org.apache.commons.logging.Log 7.8% > > > > > > > > > > > org.apache.log4j.Logger 13.6% > > > > > > > > > > > org.ovirt.engine.core.utils.log.Log 68.8% > > > > > > > > > > > org.slf4j.Logger 2.9% > > > > > > > > > > > > > > > > > > > > > > I think we should definitely use only 1 logging > > > > > > > > > > > framework > > > > > > > > > > > for > > > > > > > > > > > the > > > > > > > > > > > whole > > > > > > > > > > > engine! > > > > > > > > > > > > > > > > > > > > > > So +1 to slf4j from me. > > > > > > > > > > > > > > > > > > > > +1 from me as well. > > > > > > > > > > > > > > > > > > +1 > > > > > > > > > > > > > > > > > +1 to slf4j. I started using that exclusively in Java > > > > > > > > projects > > > > > > > > 4 > > > > > > > > years > > > > > > > > ago > > > > > > > > :) > > > > > > > > > > > > > > > > Just be careful if we're introducing it as a new dependency. > > > > > > > > (It's > > > > > > > > provided > > > > > > > > by Fedora, but there might be conflicts if JBoss/Wildfly uses > > > > > > > > it. > > > > > > > > We > > > > > > > > should > > > > > > > > use that same version, if it does.) > > > > > > > > > > > > > > We already have a dependency to slf4j 1.7.5 in the root > > > > > > > pom.xml. > > > > > > > And > > > > > > > AFAIK > > > > > > > 1.7.2 is a part of EAP 6. > > > > > > > > > > > > The jboss we are using provides slf4j-1.6.1, while it seems to be > > > > > > patched > > > > > > to > > > > > > support varargs[1] as 1.7.x. > > > > > > > > > > Ha, you are right, inside JBoss it works, because they did the same > > > > > thing > > > > > as > > > > > with > > > > > log4j. They provide same classes as slf4j, but with their own > > > > > different > > > > > implementation with JBoss Logging backend :-( > > > > > > > > > > So if you compile with slf4j 1.7, you can use varargs even when > > > > > JBoss > > > > > tries > > > > > to tell > > > > > us it provides slf4j 1.6 ... > > > > > > > > > > > As standalone at fedora there is slf4j which is compatible and at > > > > > > rhel > > > > > > there > > > > > > is slf4j-eap6 both are 1.7.x. > > > > > > However for centos we use jpackage which provides only 1.6.1[2]. > > > > > > So for standalone packages we may experience issues if were build > > > > > > using > > > > > > varargs. > > > > > > > > > > > > [1] logger.debug("format", obj1, obj2, obj3, ...) > > > > > > [2] http://jpackage.org/browser/rpm.php?jppversion=6.0&id=12435 > > > > > > > > > > AFAIK the only non JBoss usage of logging is at engine-config and > > > > > engine-manage-domains. > > > > > So we have 2 options: > > > > > > > > > > 1) Use log4j in engine-config and engine-manage-domains (current > > > > > status) > > > > > and use > > > > > slf4j in the rest of engine > > > > > > > > > > 2) Package slf4j 1.7.x as our dependency > > > > > > > > > > I would prefer option 1). > > > > > > > > > > > > > No... we use jboss modules within these, so you actually using jboss > > > > version. > > > > > > Not entirely true. We are using JBoss version of log4j to configure > > > logging. > > > But we cannot use slf4j provided by JBoss, because it can use as a > > > backend > > > only JBoss Logging and not log4j. I just verified that if slf4j is used > > > in engine-manage-domains, it's not logged to the file configured by > > > log4j. > > > > > > > The only one that does not use jboss modules is dwh, in which we do > > > > not > > > > control logging anyway. > > > > We just need to make sure that standalone application either use > > > > commons-logging (primitive) or slf4j-1.6.x for now. > > > > And in either case to use java.util.loggings as infa and not log4j if > > > > not > > > > too > > > > late for that. > > > > > > In java.utils.logging you cannot use varargs in simple way (which is > > > for > > > me > > > one of the main reason to use slf4j): > > > > > > log.info("Hello: {} {} {}", p1, p2, p3); > > > > > > but you have to create new array of params: > > > > > > log.info("Hello: {} {} {}", new Object[] { p1, p2, p3}); > > > > > > or format message outside logging framework: > > > > > > log.info(String.format("Hello: %s %s %s", p1, p2, p3)); > > > > > > And this "external formatting" is the only way for commons-logging > > > framework. > > > > You did not understand. > > Well, I'm not sure I understand even now, but see my response :-) > > > 1. use log4j or apache commons within application. > > That's not a good idea because both doesn't support simple varargs. > We want use slf4j to be able to use this: > > log.info("Hello: {} {} {}", p1, p2, p3); > I am sorry, had a typo... it should have been: 1. use slf4j or apache commons within application.

> > > 2. use java.logging as logging infra. > > Well, AFAIK JBoss reimplements java.logging backend and redirects > it to its own backend (JBoss Logging). No sure, if we will be able > (or want) to bypass this redirection and use java.logging as backend > for engine. Not to mention, there will always be server.log for JBoss > infra logging. > > And for engine-manage-domains and engine-config we would have to > drop command line configuration using log4j introduced in 3.5 and > for next version change it to java.logging configuration > > So personally I don't see any benefit of this change for users nor > developers ... yes, and drop the usage of log4j entirely.

> > > > > > > > > > > > > > > Btw in RHEL7 there is packaged slf4j 1.7.5 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Note that GWT UI code uses java.util.logging exclusively > > > > > > > > > > to > > > > > > > > > > do > > > > > > > > > > all > > > > > > > > > > logging. > > > > > > > > > > (GWT emulates java.util.logging API and provides log > > > > > > > > > > handlers > > > > > > > > > > for > > > > > > > > > > use > > > > > > > > > > on > > > > > > > > > > client side such as console.log() or > > > > > > > > > > stdout/DevMode-during-debug > > > > > > > > > > handlers.) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > And once we agree to 1 logging framework, I can start > > > > > > > > > > > preparing > > > > > > > > > > > patches > > > > > > > > > > > to > > > > > > > > > > > use it. > > > > > > > > > > > > > > > > > > > > > > ----- Original Message ----- > > > > > > > > > > > > From: "Yair Zaslavsky" <yzaslavs(a)redhat.com&gt; > > > > > > > > > > > > To: devel(a)ovirt.org > > > > > > > > > > > > Sent: Friday, June 13, 2014 8:15:55 AM > > > > > > > > > > > > Subject: [ovirt-devel] Question/thoughts about our > > > > > > > > > > > > engine > > > > > > > > > > > > logging > > > > > > > > > > > > framework > > > > > > > > > > > > > > > > > > > > > > > > Hi all, > > > > > > > > > > > > During my recent work on AAA, I was suggested by Juan > > > > > > > > > > > > Hernandez > > > > > > > > > > > > to > > > > > > > > > > > > use > > > > > > > > > > > > slf4j > > > > > > > > > > > > logging framework which serves as a facade for other > > > > > > > > > > > > logging > > > > > > > > > > > > frameworks > > > > > > > > > > > > (including java utils logging which is now used by > > > > > > > > > > > > jboss), > > > > > > > > > > > > log4j > > > > > > > > > > > > and > > > > > > > > > > > > others. > > > > > > > > > > > > I have accepted Juan's offer, and then when looking > > > > > > > > > > > > at > > > > > > > > > > > > our > > > > > > > > > > > > LogFactory > > > > > > > > > > > > class > > > > > > > > > > > > I > > > > > > > > > > > > have noticed we use commons logging. > > > > > > > > > > > > > > > > > > > > > > > > Several thoughts/questions - > > > > > > > > > > > > A. Why continue use our own wrapper as slf4j is > > > > > > > > > > > > already > > > > > > > > > > > > a > > > > > > > > > > > > facade. > > > > > > > > > > > > b. I think we should move cross java code to slf4j. > > > > > > > > > > > > What > > > > > > > > > > > > do > > > > > > > > > > > > you > > > > > > > > > > > > think > > > > > > > > > > > > on > > > > > > > > > > > > this > > > > > > > > > > > > point? > > > > > > > > > > > > > > > > > > > > > > > > Some reading material - > > > > > > > > > > > > > > > > > > > > > > > > http://javarevisited.blogspot.com.au/2013/08/why-use-sl4j-over-log4j-for-... > > > > > > > > > > > > http://stackoverflow.com/questions/3222895/what-is-the-issue-with-the-run... > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Yair > > > > > > > > > > > > _______________________________________________ > > > > > > > > > > > > Devel mailing list > > > > > > > > > > > > Devel(a)ovirt.org > > > > > > > > > > > > http://lists.ovirt.org/mailman/listinfo/devel > > > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > > > > > Devel mailing list > > > > > > > > > > > Devel(a)ovirt.org > > > > > > > > > > > http://lists.ovirt.org/mailman/listinfo/devel > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > > > > Devel mailing list > > > > > > > > > > Devel(a)ovirt.org > > > > > > > > > > http://lists.ovirt.org/mailman/listinfo/devel > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > > > Devel mailing list > > > > > > > > > Devel(a)ovirt.org > > > > > > > > > http://lists.ovirt.org/mailman/listinfo/devel > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > > Devel mailing list > > > > > > > > Devel(a)ovirt.org > > > > > > > > http://lists.ovirt.org/mailman/listinfo/devel > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > Devel mailing list > > > > > > > Devel(a)ovirt.org > > > > > > > http://lists.ovirt.org/mailman/listinfo/devel > > > > > > > > > > > > > > > > > > > > > > > > > > > >