X-CGP-ClamAV-Result: CLEAN X-VirusScanner: Niversoft's CGPClamav Helper v1.22.2a (ClamAV engine v0.102.2) X-Junk-Score: 0 [] X-KAS-Score: 0 [] From: "OCsite" Received: from smtp-beta-2.zoner.com ([217.198.120.70] verified) by post.selbstdenker.com (CommuniGate Pro SMTP 6.3.3) with ESMTPS id 25603744 for webobjects-dev@wocommunity.org; Sun, 21 Mar 2021 19:54:25 +0100 Received-SPF: none receiver=post.selbstdenker.com; client-ip=217.198.120.70; envelope-from=ocs@ocs.cz Received: from smtp.zoner.com (smtp.zoner.com [217.198.120.6]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp-beta-2.zoner.com (Postfix) with ESMTPS id DB8A418002C8; Sun, 21 Mar 2021 19:54:04 +0100 (CET) Received: from macbook-pro.ocsluj (unknown [77.240.103.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: ocs@ocs.cz) by smtp.zoner.com (Postfix) with ESMTPSA id 2BAF93000068; Sun, 21 Mar 2021 19:54:04 +0100 (CET) Message-Id: Content-Type: multipart/alternative; boundary="Apple-Mail=_9CD64398-3128-4CA4-8B94-EDA1F70B7E79" Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.120.23.2.4\)) Date: Sun, 21 Mar 2021 19:54:03 +0100 Subject: Re: [WO-DEV] ERXObjectStoreCoordinatorSynchronizer woes In-Reply-To: To: WebObjects & WOnder Development References: X-Mailer: Apple Mail (2.3608.120.23.2.4) --Apple-Mail=_9CD64398-3128-4CA4-8B94-EDA1F70B7E79 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Aaron, thanks! The app is definitely fully initialised (import is run from a = web page; besides, often it happens not at the 1st time, but later, 6th = import or so). In a sense, I do not use the stuff, that is, not actively = =E2=80=94 I just create a new OSC to get a separate EO stack with its = own database channel. All the other stuff sort of happens as a result :) Now though, very preliminarily, it seems the problem might depend on the = classpath. What the! Namely, it looks like - it does happen if JavaFoundation and JavaWebObjects precede the ER = stuff; - so far, it never happened if ERExtensions and ERJars precede = JavaFoundation and JavaWebObjects (that, of course, is inconclusive, = given the randomness of the issue). Looks like WOnder overrides some WO functionality, and unless it is = first on classpath, it might lead to problems. Very weird, especially = that it does not check whether tricks it relies on really happened or = not :-O I wonder if this is really the culprit... Thanks and all the best, OC > On 21 Mar 2021, at 17:05, Aaron Rosenzweig = wrote: >=20 > Hi OC,=20 >=20 > Check to be sure your import task is only started after the app has = finished loading, not during the launch of the app. If you call too = early in the startup phase your ModelGroups, etc, may not be setup yet. = That=E2=80=99s what it sort of looks like from your stack trace because = you have a null pointer inside of EOModelGroup which is a NeXT/Apple = object, not even a WOnder one.=20 >=20 > If you double check and are sure you don=E2=80=99t kick off a = concurrent thread before the app has finished loading=E2=80=A6 then = I=E2=80=99m not sure. You may have to revisit your use of the ERX = messaging coordinators. I=E2=80=99ve never used them so I don=E2=80=99t = have experience to share. =46rom where I stand they sound =E2=80=9Ccool=E2= =80=9D but I don=E2=80=99t get the use case. I get that people want = =E2=80=9Cfresh=E2=80=9D data and if every edit messages to all the other = ObjectStoreCoordinators then everybody is fresh all the time! Cool! but = at what cost? Does every instance need to fault in objects that people = may never see? If someone is editing the same data, and they get an = update from some other thread, what then? who wins? Chatter is expensive = on CPU / network too. Seems to me that if people want =E2=80=9Cfresh=E2=80= =9D then the best thing is to not sync but to get fresh data on the page = that you are at by setting the timestamp lag to something small like 2 = seconds. For a statistics page maybe avoid EOF altogether, use a direct = fetch of SQL.=20 >=20 >> On Mar 21, 2021, at 12:01 AM, OCsite > wrote: >>=20 >> Hi there, >>=20 >> occasionally (not too often), we are running a background import = task, which uses its own EO stack: at launch, it creates a new = EOObjectStoreCoordinator (and for it it creates an ERXEC and uses it to = import data). When done and saved, the coordinator is disposed and = released. The rationale is that the imported data might be big and we = don't want to limit normal workers processing to wait until the import = saves its results into the database. >>=20 >> For a long long time it worked reliably and without a glitch. >>=20 >> Lately, it often (though by far not each time!) happens that >>=20 >> (i) a save in the background task reports the following exception: >>=20 >> =3D=3D=3D >> 04:38:38.600 ERROR java.lang.NullPointerException = //log:er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer = [ERXOSCProcessChanges] >> NullPointerException >> at = com.webobjects.eoaccess.EOModelGroup.modelGroupForObjectStoreCoordinator(E= OModelGroup.java:795) >> at = er.extensions.eof.ERXEOAccessUtilities.databaseContextForEntityNamed(ERXEO= AccessUtilities.java:1086) >> at = er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer$ProcessChangesQueu= e._process(ERXObjectStoreCoordinatorSynchronizer.java:509) >> at = er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer$ProcessChangesQueu= e.process(ERXObjectStoreCoordinatorSynchronizer.java:540) >> at = er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer$ProcessChangesQueu= e.run(ERXObjectStoreCoordinatorSynchronizer.java:617) >> ... skipped 1 stack elements >> =3D=3D=3D >>=20 >> (ii) after that, usually no more exceptions are reported, but the = ERXObjectStoreCoordinatorSynchronizer does not seem to work properly = anymore, and it often happens that the changes done in the background = task are not visible in the main OSC for awhile. >>=20 >> =46rom the user's perspective it usually means that the import is = finished, but the imported data is not visible for a long long time = (does not seem to be just a fetchTimestampLag, for newly logged-in users = with their new sessions and new ECs still don't see the imported data = for awhile. Frankly, I can't see what the H. might be the culprit :/ ) >>=20 >> (iii) another problem which seems to be also caused (perhaps = indirectly) by the above exception is that the application cannot be = normally quit from JavaMonitor, reporting upon an attempt >>=20 >> =3D=3D=3D >> 04:33:43.441 ERROR Exception caught: null >> ... ... >> IllegalStateException: Attempted to stop the ProcessChangesQueue when = it wasn't already running >> at = er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer$ProcessChangesQueu= e.stop(ERXObjectStoreCoordinatorSynchronizer.java:637) >> at = er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer.stopRemoteSynchron= izer(ERXObjectStoreCoordinatorSynchronizer.java:132) >> ... skipped 8 stack elements >> at = er.extensions.appserver.ERXApplication.terminate(ERXApplication.java:2861)= >> ... ... >> =3D=3D=3D >>=20 >> Any idea what might be the culprit and how to fix it? >>=20 >> Thanks and all the best, >> OC >>=20 >=20 --Apple-Mail=_9CD64398-3128-4CA4-8B94-EDA1F70B7E79 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Aaron,

thanks! The app is definitely fully initialised (import is = run from a web page; besides, often it happens not at the 1st time, but = later, 6th import or so). In a sense, I do not use the stuff, that is, = not actively =E2=80=94 I just create a new OSC to get a separate EO = stack with its own database channel. All the other stuff sort of happens = as a result :)

Now though, very preliminarily, it seems the problem might = depend on the classpath. What the! Namely, it looks like

- it does happen if = JavaFoundation and JavaWebObjects precede the ER stuff;
- so far, it never happened if ERExtensions = and ERJars precede JavaFoundation and JavaWebObjects = (that, of course, is inconclusive, given the randomness of the = issue).

Looks = like WOnder overrides some WO functionality, and unless it is first on = classpath, it might lead to problems. Very weird, especially that it = does not check whether tricks it relies on really happened or not = :-O

I wonder = if this is really the culprit...

Thanks and all the best,
OC


On 21 Mar 2021, at 17:05, = Aaron Rosenzweig <webobjects-dev@wocommunity.org> wrote:

Hi OC, 

Check to be sure your = import task is only started after the app has finished loading, not = during the launch of the app. If you call too early in the startup phase = your ModelGroups, etc, may not be setup yet. That=E2=80=99s what it sort = of looks like from your stack trace because you have a null pointer = inside of EOModelGroup which is a NeXT/Apple object, not even a WOnder = one. 

If = you double check and are sure you don=E2=80=99t kick off a concurrent = thread before the app has finished loading=E2=80=A6 then I=E2=80=99m not = sure. You may have to revisit your use of the ERX messaging = coordinators. I=E2=80=99ve never used them so I don=E2=80=99t have = experience to share. =46rom where I stand they sound =E2=80=9Ccool=E2=80=9D= but I don=E2=80=99t get the use case. I get that people want = =E2=80=9Cfresh=E2=80=9D data and if every edit messages to all the other = ObjectStoreCoordinators then everybody is fresh all the time! Cool! but = at what cost? Does every instance need to fault in objects that people = may never see? If someone is editing the same data, and they get an = update from some other thread, what then? who wins? Chatter is expensive = on CPU / network too. Seems to me that if people want =E2=80=9Cfresh=E2=80= =9D then the best thing is to not sync but to get fresh data on the page = that you are at by setting the timestamp lag to something small like 2 = seconds. For a statistics page maybe avoid EOF altogether, use a direct = fetch of SQL. 

On Mar 21, 2021, at 12:01 AM, OCsite <webobjects-dev@wocommunity.org> wrote:

Hi there,

occasionally (not too = often), we are running a background import task, which uses its own EO = stack: at launch, it creates a new EOObjectStoreCoordinator (and for it it creates an ERXEC and uses it to import data). When done and saved, = the coordinator is disposed and released. The rationale is that the = imported data might be big and we don't want to limit normal workers = processing to wait until the import saves its results into the = database.

For = a long long time it worked reliably and without a glitch.

Lately, it often (though = by far not each time!) happens that

(i) a save in the background task = reports the following exception:

=3D=3D=3D
04:38:38.600 ERROR = java.lang.NullPointerException       = //log:er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer = [ERXOSCProcessChanges]
NullPointerException
  = at = com.webobjects.eoaccess.EOModelGroup.modelGroupForObjectStoreCoordinator(E= OModelGroup.java:795)
  at = er.extensions.eof.ERXEOAccessUtilities.databaseContextForEntityNamed(ERXEO= AccessUtilities.java:1086)
  at = er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer$ProcessChangesQueu= e._process(ERXObjectStoreCoordinatorSynchronizer.java:509)
  = at = er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer$ProcessChangesQueu= e.process(ERXObjectStoreCoordinatorSynchronizer.java:540)
  = at = er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer$ProcessChangesQueu= e.run(ERXObjectStoreCoordinatorSynchronizer.java:617)
  = ... skipped 1 stack elements
=3D=3D=3D

(ii) after that, = usually no more exceptions are reported, but the ERXObjectStoreCoordinatorSynchronizer does not seem to = work properly anymore, and it often happens that the changes done in the = background task are not visible in the main OSC for awhile.

=46rom the user's = perspective it usually means that the import is finished, but the = imported data is not visible for a long long time (does not seem to be = just a fetchTimestampLag, for newly logged-in = users with their new sessions and new ECs still don't see the imported = data for awhile. Frankly, I can't see what the H. might be the culprit = :/ )

(iii) = another problem which seems to be also caused (perhaps indirectly) by = the above exception is that the application cannot be normally quit from = JavaMonitor, reporting upon an attempt

=3D=3D=3D
04:33:43.441 ERROR Exception caught: null
... ...
IllegalStateException: Attempted to stop the = ProcessChangesQueue when it wasn't already running
  = at = er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer$ProcessChangesQueu= e.stop(ERXObjectStoreCoordinatorSynchronizer.java:637)
  = at = er.extensions.eof.ERXObjectStoreCoordinatorSynchronizer.stopRemoteSynchron= izer(ERXObjectStoreCoordinatorSynchronizer.java:132)
     ... skipped 8 stack = elements
  at = er.extensions.appserver.ERXApplication.terminate(ERXApplication.java:2861)=
... ...
=3D=3D=3D

Any idea what might be = the culprit and how to fix it?

Thanks and all the best,
OC



= --Apple-Mail=_9CD64398-3128-4CA4-8B94-EDA1F70B7E79--