Bug 1396833 - ovirt-shell: sporadic HTTP 500 errors
Summary: ovirt-shell: sporadic HTTP 500 errors
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: ovirt-engine
Classification: oVirt
Component: AAA
Version: 4.0.5.5
Hardware: Unspecified
OS: Unspecified
unspecified
medium
Target Milestone: ovirt-4.1.0-rc
: 4.1.0
Assignee: Ravi Nori
QA Contact: Petr Matyáš
URL:
Whiteboard:
: 1379690 1396835 (view as bug list)
Depends On:
Blocks: 1301067 1416308
TreeView+ depends on / blocked
 
Reported: 2016-11-20 17:26 UTC by Markus Stockhausen
Modified: 2017-02-01 14:41 UTC (History)
8 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Cause: Using new HTTPS connection for each communication between engine and SSO module causes serious performance issues. Consequence: Fix: This fix adds connection pool to reuse existing connection for engine <-> SSO communication. Result: By default we create a connection pool on engine side to communicate with SSO module. The size of this pool is defined by ENGINE_SSO_SERVICE_CLIENT_POOL_SIZE option (default size is 10 connections). Similarly we create a connection pool on SSO side to communication with clients (only engine at the moment). The size of this pool is defined by SSO_CALLBACK_CLIENT_POOL_SIZE option (default size is 10 connections). If needed those options can be customized by creating /etc/ovirt-engine/engine.conf.d/99-custom-connection-pool.conf file with following content: ENGINE_SSO_SERVICE_CLIENT_POOL_SIZE=NNN SSO_CALLBACK_CLIENT_POOL_SIZE=MMM where NNN respectively MMM are new sizes of relevant connection pool.
Clone Of:
: 1416308 (view as bug list)
Environment:
Last Closed: 2017-02-01 14:41:10 UTC
oVirt Team: Infra
Embargoed:
rule-engine: ovirt-4.1+
rule-engine: planning_ack+
mperina: devel_ack+
lsvaty: testing_ack+


Attachments (Terms of Use)
server log (1.60 MB, text/plain)
2016-11-22 20:38 UTC, Markus Stockhausen
no flags Details
engine log (3.73 MB, text/plain)
2016-11-22 20:38 UTC, Markus Stockhausen
no flags Details
ssl log (1.39 MB, text/plain)
2016-11-22 20:51 UTC, Markus Stockhausen
no flags Details
new server log (60.71 KB, text/plain)
2016-11-30 20:14 UTC, Markus Stockhausen
no flags Details
new engine log (241.42 KB, text/plain)
2016-11-30 20:15 UTC, Markus Stockhausen
no flags Details


Links
System ID Private Priority Status Summary Last Updated
oVirt gerrit 67294 0 master MERGED core: Use persistent HTTP connections between engine and SSO 2021-02-14 14:55:32 UTC
oVirt gerrit 67724 0 master MERGED aaa: Handle session creation during clean expired user sessions 2021-02-14 14:55:32 UTC
oVirt gerrit 67742 0 ovirt-engine-4.0 MERGED aaa: Handle session creation during clean expired user sessions 2021-02-14 14:55:32 UTC
oVirt gerrit 68393 0 ovirt-engine-4.0 MERGED core: Align 'httpcomponents' version with WildFly 2021-02-14 14:55:32 UTC
oVirt gerrit 68394 0 ovirt-engine-4.0 MERGED core: Use persistent HTTP connections between engine and SSO 2021-02-14 14:55:32 UTC

Description Markus Stockhausen 2016-11-20 17:26:35 UTC
Description of problem:

ovirt-shell gives sometimes http 500 errors.


Version-Release number of selected component (if applicable):

Ovirt 4.0.5

How reproducible:

100%

Steps to Reproduce:

1) Run "list disk" loop with script:

#!/bin/sh
while [ 1 -eq 1 ]; do
  /usr/bin/ovirt-shell -c -E 'list disks' >/dev/null
  echo -n .
done

2) wait for http 500 error. Will occur once in 10-15 minutes.

Actual results:

...........................
=========================== ERROR =======================
[500] - Internal Server Error
=========================================================
=========================== ERROR =======================
command "list" is not valid or not available while not connected.
=========================================================
....................................

Expected results:

no errors.

Additional info:

content of .ovirtshellrc:

[cli]
autoconnect = True
autopage = True
[ovirt-shell]
username = admin@internal
renew_session = False
timeout = None
extended_prompt = False
url = https://<engine.host>/ovirt-engine/api
insecure = True
kerberos = False
filter = False
session_timeout = None
ca_file = None
dont_validate_cert_chain = True
key_file = None
password = <password>
cert_file = None

Comment 1 Juan Hernández 2016-11-21 08:40:44 UTC
That error message is the expected reaction of the CLI when the engine fails with a 500 error. To determine what is happening we need to take a look at the /var/log/ovirt-engine/server.log and /var/log/ovirt-engine/engine.log files. Can you share them?

Comment 2 Markus Stockhausen 2016-11-22 20:37:19 UTC
Last error:

Di 22. Nov 20:52:50 CET 2016
============================= ERROR =======================================
               [500] - Internal Server Error
=========================================================================

============================ ERROR =======================================
command "list" is not valid or not available while not connected.
==========================================================================
Di 22. Nov 20:52:50 CET 2016

server/engine logs attached

Comment 3 Markus Stockhausen 2016-11-22 20:38:06 UTC
Created attachment 1222889 [details]
server log

Comment 4 Markus Stockhausen 2016-11-22 20:38:36 UTC
Created attachment 1222890 [details]
engine log

Comment 5 Markus Stockhausen 2016-11-22 20:43:01 UTC
*** Bug 1396835 has been marked as a duplicate of this bug. ***

Comment 6 Juan Hernández 2016-11-22 20:44:35 UTC
Can you attach /var/log/httpd/ssl_access_log?

Comment 7 Markus Stockhausen 2016-11-22 20:51:40 UTC
Created attachment 1222891 [details]
ssl log

Comment 8 Juan Hernández 2016-11-23 21:03:29 UTC
Unfortunately I can't reproduce this problem, and the log messages aren't really useful. However, why trying to reproduce it, using the script provided by Markus, I see that the engine is killed by the out of memory killer of the kernel. The reason is that the RSS size grows without limit. This suggests that there is a memory leak, which may cause all kinds of strange results. I am focusing on that.

Comment 9 Oved Ourfali 2016-11-28 12:39:39 UTC
Juan - should we backport for 4.0.6/4.0.7?

Comment 10 Juan Hernández 2016-11-28 12:44:17 UTC
I am not 100% sure of the cause of the problem that Markus detected. Currently I am focusing on a possible leak of native memory, caused by the creation of multiple SSL sockets. But the problem that I can reproduce, based on that hypothesis, is a complete crash of the engine, which isn't exactly what Markus sees.

However the optimization to use persistent SSL connections is important enough to consider backporting it 4.0. It is also invasive enough to consider it very carefully. I'd prefer to wait a bit to see what Martin and Ravi think. Then we can decide what to do.

Comment 11 Juan Hernández 2016-11-28 12:48:21 UTC
By the way Markus, can you share what is the configuration of your engine? What is the amount of RAM of the machine? And the amount of RAM assigned to the engine (from /etc/ovirt-engine/engine.conf.d/10-setup-java.conf)?

Comment 12 Markus Stockhausen 2016-11-28 20:32:17 UTC
engine has 12GB RAM.

config is:

# cat /etc/ovirt-engine/engine.conf.d/10-setup-java.conf
ENGINE_HEAP_MIN="4096M"
ENGINE_HEAP_MAX="4096M"

@Juan: you are right your bugfix for the SSL pool does not directly fix the HTTP 500 error. As you might have noticed: The error logs give no real idea of the root cause.

But what I have noticed: The error occurs more often if you are running a live disk migration during the calls. To be more precise: I run

one time: 
/usr/bin/ovirt-shell -c -E 'action disk <diskname> move --storage_domain-name <targetdomain>

multiple time (to wait until migration finishes)

rdy=0
while [ $rdy -eq 0 ]; do
  sleep 10
  echo -n "."

  rdy=`/usr/bin/ovirt-shell -c -E 'list disks --query "storage = '<targetdomain>' and name = '<diskname>'"' | grep <diskname> | wc -l`
done

Comment 13 Juan Hernández 2016-11-30 13:16:08 UTC
Thanks for the additional information Markus. Unfortunately I am not able to reproduce this in my environment, even with that example. I have the suspicion that the exception is generated in the authentication layer, as that is one of the parts of the application where we don't send to the log the complete exception stack traces.

Can you enable the debug log for the AAA module? That, in general, is described here:

  https://www.ovirt.org/develop/developer-guide/engine/jmx-support

In this particular case it should be a matter of running these commands:

  echo 'ENGINE_JMX_INTERFACE=loopback' > /etc/ovirt-engine/engine.conf.d/99-jmx.conf
  systemctl restart ovirt-engine
  export JBOSS_HOME=/usr/share/ovirt-engine-wildfy
  $JBOSS_HOME/bin/jboss-cli.sh --controller=localhost:8706 --connect --user=admin@internal

Then, in the prompt of the 'jboss-cli' tool:

  /subsystem=logging/logger=org.ovirt.engine.core.aaa:add
  /subsystem=logging/logger=org.ovirt.engine.core.aaa:write-attribute(name=level,value=DEBUG)

Once that is done the AAA module will start sending messages to the 'engine.log' file, hopefully including the complete stack trace of the exception.

Once you are done collecting the results you can remove the '99-jmx.conf' file, and restart the engine, and everything will be back to the initial configuration.

Comment 14 Markus Stockhausen 2016-11-30 20:14:55 UTC
Created attachment 1226483 [details]
new server log

Comment 15 Markus Stockhausen 2016-11-30 20:15:31 UTC
Created attachment 1226484 [details]
new engine log

Comment 16 Markus Stockhausen 2016-11-30 20:16:20 UTC
Next error:

Mi 30. Nov 21:08:20 CET 2016
======================================= ERROR ========================
  status: 500
  reason: Internal Server Error
  detail: java.lang.IllegalStateException
  ====================================================================
Mi 30. Nov 21:08:22 CET 2016

logs attached

Comment 17 Juan Hernández 2016-12-01 09:07:21 UTC
This is a different error, but at least we have an stack trace for it. The relevant log message is the following:

2016-11-30 21:08:21,928 ERROR [org.ovirt.engine.core.bll.SearchQuery] (default task-62) [] Exception: java.lang.NullPointerException
        at org.ovirt.engine.core.bll.QueriesCommandBase.validatePermissions(QueriesCommandBase.java:157) [bll.jar:]

That means that there is a null pointer exception here:

  https://github.com/oVirt/ovirt-engine/blob/ovirt-engine-4.0.5.5/backend/manager/modules/bll/src/main/java/org/ovirt/engine/core/bll/QueriesCommandBase.java#L157

The code there is like this:

  return getUser().isAdmin();

The only way that can generate a null pointer exception is if the "getUser()" method returns null, and that should never happen for a an authenticated request, unless the backend session is removed in the middle of the command, which shouldn't happen either.

Ravi, can you take a look? Note that the logs contain the AAA debug info.

Comment 18 Ravi Nori 2016-12-02 02:42:33 UTC
I was able to reproduce the issue, it happens when a session is created during the execution of cleanExpiredUsersSessions after the session status was retrieved from SSO.

Comment 19 Markus Stockhausen 2016-12-02 07:46:11 UTC
Please backport at least the session handling fix of Ravi Nori to 4.0.x.

Comment 20 Juan Hernández 2016-12-02 08:03:06 UTC
I agree with Markus that this should be backported to 4.0.z. Martin, can you re-target?

Comment 21 Martin Perina 2016-12-02 09:27:55 UTC
I agree, let's finish the fix for master and when done decide how to fix that in 4.0.z

Comment 22 Martin Perina 2016-12-06 14:07:09 UTC
*** Bug 1379690 has been marked as a duplicate of this bug. ***

Comment 23 Martin Perina 2016-12-13 09:06:59 UTC
Backport to ovirt-engine-4.0 branch is needed

Comment 24 Sandro Bonazzola 2017-01-25 07:55:24 UTC
4.0.6 has been the last oVirt 4.0 release, please re-target this bug.

Comment 25 Martin Perina 2017-01-25 08:52:22 UTC
Setting flags back to allow cloning

Comment 27 Petr Matyáš 2017-01-31 13:26:33 UTC
Verified on 4.1.0-9


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