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: "Aaron Rosenzweig" Received: from mail-qk1-f178.google.com ([209.85.222.178] verified) by selbstdenker.ag (CommuniGate Pro SMTP 6.3.3) with ESMTPS id 25604408 for webobjects-dev@wocommunity.org; Mon, 22 Mar 2021 02:37:33 +0100 Received-SPF: none receiver=post.selbstdenker.com; client-ip=209.85.222.178; envelope-from=recurve@cocoanutstech.com Received: by mail-qk1-f178.google.com with SMTP id y18so9090395qky.11 for ; Sun, 21 Mar 2021 18:37:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chatnbike.com; s=chatnbike; h=from:message-id:mime-version:date:subject:in-reply-to:to:references; bh=BWPWa2O8FKvrisWKqi+1ZRJAm+dsYBqPFHVoGlZZ1x0=; b=PMT2cTKLNkpJS0Ak13z0tF7T1g47ugm3jiE0fd/9DCeIpFaAZRJLVvWwqfCW2Xv/Vp 7WPOG5WnUV0Bt7YxA21ZCP7hyz1KdTzurKT5DI9aveMUYHZ/1U5qjz7HofnEs/rH9+Sa c8xvQvl09NdV0l8jYivXXN/5jceLxnqKWg174= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:message-id:mime-version:date:subject :in-reply-to:to:references; bh=BWPWa2O8FKvrisWKqi+1ZRJAm+dsYBqPFHVoGlZZ1x0=; b=giVe02S7WCru6x1Xs6EheanBRhDwWAuYMrJ6tAgc7WNx4dDfXeApx+CZpjfUfmrYdj kIhfbEnca1e1kYfsrFCF0mr9XWPRYu8ndjwXUQdaLe6FnO1qy//VmwH+bJVyu5Nf+f6N ZQlTEp3HGXdsRNcflPCufSNK+o9wY1mgLWdAOKi3mNQWa1M1HNM0vfLfDW4ltpAJ4o5h 2zHCbQ95X3wMaoL8wa50Zlth577BAxbv0s7HRxJqgrLbJGv93bzEtBR1pclxPunb83og L723R9hODADGXfLHc5+/+lHqOrRk9abOM3wkJsOeHvCE54ARFqeV2r49z5DnnH/iHjzA wYNg== X-Gm-Message-State: AOAM530sV6MCLpHACQlEbHlUnJEds6i7hgDzJv+BmlKmsPtKbZ1dv3Ws EQK/JJxvgMRpCLWfbJwdiqJBzb+y1YTvgqKi X-Google-Smtp-Source: ABdhPJyHGgf3Y4FLhUbkmq1O2MSucniNgVyctB35O0ukTR0fuELulSO9Y9Juh1YuTKF5/HX4A4tfvg== X-Received: by 2002:ae9:e80b:: with SMTP id a11mr8806525qkg.65.1616377031368; Sun, 21 Mar 2021 18:37:11 -0700 (PDT) Return-Path: Received: from mac-pro.lan (pool-173-79-35-204.washdc.fios.verizon.net. [173.79.35.204]) by smtp.gmail.com with ESMTPSA id j24sm9724184qka.67.2021.03.21.18.37.10 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 21 Mar 2021 18:37:10 -0700 (PDT) Message-Id: <0FC241F5-E598-44AF-835F-E475500E01AA@chatnbike.com> Content-Type: multipart/alternative; boundary="Apple-Mail=_8C19E67F-3CA2-4FC5-8067-1A3F259F10E8" Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.60.0.2.21\)) Date: Sun, 21 Mar 2021 21:37:10 -0400 Subject: Re: [WO-DEV] ERXObjectStoreCoordinatorSynchronizer woes In-Reply-To: To: WebObjects & WOnder Development References: X-Mailer: Apple Mail (2.3654.60.0.2.21) --Apple-Mail=_8C19E67F-3CA2-4FC5-8067-1A3F259F10E8 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Hi OC, It is true that the order of the JARs does matter and it may be causing = issues here=E2=80=A6 but the order definitely matters.=20 Take =E2=80=9CNSArray=E2=80=9D for example. That=E2=80=99s a NeXT/Apple = class right? Yes & No. WOnder provides their own version of it. Wonders = version has the same name and is in the same package: = com.webobjects.foundation=20 Why did we, as a community, do that? In the early days it was so that = NSArray could use generics=E2=80=A6 then in WO 5.4.3 they fixed that on = the Apple side so=E2=80=A6 I=E2=80=99m not sure, offhand, why we still = have our own version of NSArray but=E2=80=A6 we do. And there are other = classes like this. To make it =E2=80=9Cwork=E2=80=9D you Java takes the = first package/Class it finds and uses it all the time. First JAR file = wins, so the Wonder stuff must come before the Apple stuff.=20 > On Mar 21, 2021, at 2:54 PM, OCsite = wrote: >=20 > Aaron, >=20 > 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 :) >=20 > Now though, very preliminarily, it seems the problem might depend on = the classpath. What the! Namely, it looks like >=20 > - 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). >=20 > 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 >=20 > I wonder if this is really the culprit... >=20 > Thanks and all the best, > OC >=20 >=20 >> 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 >=20 --Apple-Mail=_8C19E67F-3CA2-4FC5-8067-1A3F259F10E8 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Hi = OC,

It is true that = the order of the JARs does matter and it may be causing issues here=E2=80=A6= but the order definitely matters. 

Take =E2=80=9CNSArray=E2=80=9D for = example. That=E2=80=99s a NeXT/Apple class right? Yes & No. WOnder = provides their own version of it. Wonders version has the same name and = is in the same package: com.webobjects.foundation 

Why did we, as a = community, do that? In the early days it was so that NSArray could use = generics=E2=80=A6 then in WO 5.4.3 they fixed that on the Apple side = so=E2=80=A6 I=E2=80=99m not sure, offhand, why we still have our own = version of NSArray but=E2=80=A6 we do. And there are other classes like = this. To make it =E2=80=9Cwork=E2=80=9D you Java takes the first = package/Class it finds and uses it all the time. First JAR file wins, so = the Wonder stuff must come before the Apple stuff. 


On Mar 21, 2021, at 2:54 PM, OCsite <webobjects-dev@wocommunity.org> wrote:

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=_8C19E67F-3CA2-4FC5-8067-1A3F259F10E8--