Yes, I will collect the logs. It may take a day or so though…
From: Reka Thirunavukkarasu [mailto:[email protected]]
Sent: 14 July 2015 13:54
To: dev
Cc: Shaheedur Haque (shahhaqu)
Subject: Re: ***UNCHECKED*** Problem with Stratos 4.1 failover (was RE:
Problems with Stratos 4.1 failover and autohealing)
Hi Shaheed,
As i went through the logs(wso2carbon.log and wso2-cep-trace.log) of
octl-02-after, identified that there is a possibility for the member fault to
occur as cartridge agent didn't publish the events for more than one minute
from 00:53:24 to 00:55:09 ([2], [3]) which is obviously more than one minute
where the cartridge agent health publishing interval is 15s ([1], [2]). I
observed this sequence([1], [2], [3]) in the wso2-cep-trace.log. It has
happened intermittently. Please see below for the details. Member fault
occur[4] in stratos side at 00:54:34 as the last event from cartridge agent was
marked as 00:53:24 [2]. The next event from cartridge agent received at
00:55:09. So, we will need to investigate at the cartridge agent side why it
failed sent the health stats intermittently even after everything back to
normal as i could see that cartridge agent was publishing health stat after
octl-02 came without any issue for nearly two minutes Eg: [1] and [2]
Is it possible for you to get the cartridge agent logs? I know that it is
little bit hard as stratos will immediately terminate the instance. But if you
could tail the logs, then i believe that you can get the logs from where you
tailed.
[1]
00:53:09,347 [-] [DataBridge-Core-pool-2-thread-8] INFO EVENT_TRACE_LOGGER
TenantId=-1234 : Input Event Adaptor : DefaultWSO2EventInputAdaptor, received
Event{
streamId='cartridge_agent_health_stats:1.0.0',
timeStamp=0,
metaData=null,
correlationData=null,
payloadData=[cartridge-proxy.cartridge-proxy.cartridge-proxy.domain,
cartridge-proxy-1, RegionOne,
cartridge-proxy.cartridge-proxy.cartridge-proxy.domainc1dd3d8b-95ed-439c-96be-daaac2cb15a3,
whole-region, load_average, 0.0],
arbitraryDataMap={},
}
[2]
00:53:24,345 [-] [DataBridge-Core-pool-2-thread-4] INFO EVENT_TRACE_LOGGER
TenantId=-1234 : Input Event Adaptor : DefaultWSO2EventInputAdaptor, received
Event{
streamId='cartridge_agent_health_stats:1.0.0',
timeStamp=0,
metaData=null,
correlationData=null,
payloadData=[cartridge-proxy.cartridge-proxy.cartridge-proxy.domain,
cartridge-proxy-1, RegionOne,
cartridge-proxy.cartridge-proxy.cartridge-proxy.domainc1dd3d8b-95ed-439c-96be-daaac2cb15a3,
whole-region, load_average, 0.0],
arbitraryDataMap={},
}
[3]
00:55:09,349 [-] [DataBridge-Core-pool-2-thread-10] INFO EVENT_TRACE_LOGGER
TenantId=-1234 : Input Event Adaptor : DefaultWSO2EventInputAdaptor, received
Event{
streamId='cartridge_agent_health_stats:1.0.0',
timeStamp=0,
metaData=null,
correlationData=null,
payloadData=[cartridge-proxy.cartridge-proxy.cartridge-proxy.domain,
cartridge-proxy-1, RegionOne,
cartridge-proxy.cartridge-proxy.cartridge-proxy.domainc1dd3d8b-95ed-439c-96be-daaac2cb15a3,
whole-region, load_average, 0.0],
arbitraryDataMap={},
}
[4] TID: [0] [STRATOS] [2015-07-14 00:54:34,818] INFO
{org.apache.stratos.cep.extension.FaultHandlingWindowProcessor} - Faulty
member detected [member-id]
cartridge-proxy.cartridge-proxy.cartridge-proxy.domainc1dd3d8b-95ed-439c-96be-daaac2cb15a3
with [last time-stamp] 1436835204346 [time-out] 60000 milliseconds
1436835204346 ==> 14 Jul 2015 00:53:24 GMT
Thanks,
Reka
On Tue, Jul 14, 2015 at 5:21 PM, Reka Thirunavukkarasu
<[email protected]<mailto:[email protected]>> wrote:
Thanks Shaheed for the update on the failover issue..I will go through the logs
and share the observation further..
Thanks,
Reka
On Tue, Jul 14, 2015 at 2:39 PM, Shaheedur Haque (shahhaqu)
<[email protected]<mailto:[email protected]>> wrote:
This thread breaks out the failover issue previously reported in the thread
below.
Scenario
1. Start 2 orchestration controllers, octl-01 and octl-02. At this stage,
Stratos comes up on octl-01.
2. Shortly later, launch two single VM applications (cisco-sample and
cartridge-proxy)
3. Some time later, launch three more single VM applications (di-000-001
to di-000-003)
4. Some time later, kill octl-01
5. Wait
6. About 60 seconds later or so, DNS switched to point Cartridge Agents to
octl-02 and then Stratos comes up on octl-02.
Expected result
• New Stratos instance picks up the old cartridges and carries on
Actual results
• The new Startos instance seems to think the old cartridges are dead or
something, and spins up new VMs.
• All sorts of exceptions are being thrown.
Supporting info
Two tarballs attached. The “before” set was taken before step 4, the “after”
set was taken after step 6. Each contains tarballs for octl-01 and octl-02.
Thus, in the first, the wso2logs are at
• tech-support-octl-01.tar, under /var/log/apache-stratos
and in the second, they are at
• tech-support-octl-02.tar, under /var/log/apache-stratos
From: Shaheedur Haque (shahhaqu)
Sent: 07 July 2015 12:10
To: [email protected]<mailto:[email protected]>
Subject: Problem with Stratos 4.1 autohealing (was RE: Problems with Stratos
4.1 failover and autohealing)
I met with several of the wso2 team, and we agreed the following next steps:
1. Treat the “Stratos failover” issue as separate from the “duplicate
instances” issue, and use a new thread for the former, keeping this thread for
the latter.
2. The lack of synchronisation between the cleanup of the faulty VMs and
the startup of the replacement VMs was noted.
a. It was mentioned that the period of overlap should be seconds, perhaps
upto 60s.
b. I noted that for many of our scenarios, where the hardware is 1:1
mapped to VMs (i.e. neither over-subscribed nor under-subscribed), the overlap
may be a problem. I will consult with others and confirm. Imesh ack’d this
point.
c. I will provide the wso2 logs for my test case (summarised below).
d. I will check with the test team where the problem was originally
detected if this is a transient (upto 60s) or long-lived, and gather logs as
needed.
From: Imesh Gunaratne [mailto:[email protected]<mailto:[email protected]>]
Sent: 06 July 2015 17:11
To: dev
Subject: Re: Problems with Stratos 4.1 failover and autohealing
On Mon, Jul 6, 2015 at 8:13 PM, Akila Ravihansa Perera
<[email protected]<mailto:[email protected]>> wrote:
If it detects that cartridge agent has not published any health event within
the given time window (60mins), it will publish the MemberFault event.
This should be 60 seconds.
On Mon, Jul 6, 2015 at 8:13 PM, Akila Ravihansa Perera
<[email protected]<mailto:[email protected]>> wrote:
Hi Shaheed,
Regarding Stratos fail-over scenario, by looking at the logs it seems that
there are multiple member fault cases detected by CEP. This
FaultHandlingWindowProcessor [1] running inside CEP is implemented to check for
health stats published by cartridge agents. It does not check whether actual VM
or processes running inside the VM is active or not. If it detects that
cartridge agent has not published any health event within the given time window
(60mins), it will publish the MemberFault event.
Ideally this should not happen regardless of whether the deployment is HA or
not. Because FaultHandlingWindowProcessor will count the 60mins interval from
the point Stratos server started. Only reason I could think of which may have
caused these faulty member logs is Stratos (or external CEP) did not receive
health stats published by cartridge agents on time.
Are you running Stratos in single-JVM mode? If so, I'd highly recommend that
you deploy the CEP profile separately. Please refer to [2] for reference
deployment architecture of Stratos HA setup.
Regarding your second concern; Kill multiple Cartridges, I believe your concern
is that the first message relating to recovery of the CPS came 66s after faulty
member detection and recovery of other VMs started before that. I'd like to
summarize few points regarding Stratos recovery process which I think will
explain that behavior.
- Stratos detects faulty members only by checking the health stats published
by cartridge agent and not by checking the existence of the actual VM.
- Upon detecting such faulty member, CEP will publish a faulty member event
and after receiving such event AS will move that instance to obsolete list. AS
will iterate over this obsolete list and try to terminate those instances via
CC. When the termination is complete, CC will publish member terminated event,
upon receiving that AS will remove that member from obsolete list.
- If CC fails to terminate the instance, it will keep retrying until a
obsolete member timeout interval has passed. When the timeout expires, AS will
forcefully remove that member from obsolete list.
- Stratos will not try to re-spawn the faulty instance right after detecting
it. This recovery process is triggered by the Cluster monitor object. There is
a Drools logic which gets executed periodically (monitor interval is
configurable, default is 90s) which will execute the min-check rule, scale-up
rule and scale-down rule and decide whether to spawn new instances. So this
recovery process could take some time depending on your monitor interval.
So in retrospect;
- There is no way to control which cluster monitor gets executed first, so
therefore it is possible that CPS recovery takes place after other VMs.
- The reason for seeing lot of termination logs is because Stratos continuously
tries to terminate those faulty members until obsolete member timeout has
expired. This could occur if the actual VM was killed manually or by other
means.
However, we need to figure out why you got these faulty member events. Could
you send us the CEP trace log for further analysis? Also you can enable debug
logs for FaultHandlingWindowProcessor class to get more insights as to what's
going on.
I hope this would explain your concerns. We can have a Hangout session to
discuss this further.
[1]
https://cwiki.apache.org/confluence/display/STRATOS/4.1.0+Configuring+HA+in+Single+JVM+Mode+on+EC2
[2]
https://github.com/apache/stratos/blob/master/extensions/cep/stratos-cep-extension/src/main/java/org/apache/stratos/cep/extension/FaultHandlingWindowProcessor.java
Thanks.
On Mon, Jul 6, 2015 at 5:00 PM, Shaheedur Haque (shahhaqu)
<[email protected]<mailto:[email protected]>> wrote:
Hi,
I am seeing some issues around Stratos 4.1 around failover on the one hand
(i.e. stop one running instance of Startos, start another as a replacement),
and autohealing (i.e. a Cartridge dies and need to be replaced by Stratos)
which feel as though they might have a common cause, so I am lumping them
together for now. I’ll explain the two scenarios as I can…and the attach some
logs explaining one scenario in detail.
Failover of Stratos
The situation here is that I have 3 servers, all running MySQL in active-active
mode, and Stratos running on at most one of them under Pacemaker control. The
test case is that I kill the server (actually a VM) running Stratos, and
Pacemaker responds by starting Stratos on one of the remaining servers. Around
the time of the action, there is no ongoing REST activity in terms of defining
new Cartridges, or Applications or anything like that.
• Expected result: the replacement Stratos instance “acquires” the
running Cartridges, and the system continues without killing/replacing any
Cartridges.
• Actual result: all Cartridges are kill and restarted.
Kill multiple Cartridges
I have a test where several Cartridges are killed at the same time as follows.
We have a Cartridge Proxy Server (CPS) that hosts the (Java) Cartridge agent
for VMs which cannot run one natively. The CPS therefore runs N+1 JCAs, one for
itself plus N for the Cartridges it is proxying. Killing the CPS therefore
causes all N+1 JCAs to disappear, and from a Startos point of view, all N+1 VMs
need to be restarted.
• Expected result: each Cartridges is replaced by Stratos.
• Actual result: looking at the Stratos logs, it seems that there is a
race between the termination logic which cleans up as old cluster members dies
against the startup logic which is spinning up replacement VMs for the
terminated ones.
Both cases previously seemed to work fine, where we *think* previously means
versions of Stratos 4.1 dating back ~3 weeks or so. I attach a series of log
extracts for the second scenario; I suspect this also covers the first, even if
not, at least we can start here.
1. Original spin up of CPS is at 2015-06-11 19:50:20,585. CPS fault seen
around 2015-06-12 18:54:51, contemporaneously, all the other faults are seen:
ID: [0] [STRATOS] [2015-06-12 18:54:51,788] INFO
{org.apache.stratos.cep.extension.FaultHandlingWindowProcessor} - Faulty
member detected [member-id]
di-000-007.di-000-007.cisco-qvpc-sf-0.domain88ef85b5-5ec6-4d4e-b7b2-1ab9d3f7b160
with [last time-stamp] 1434135185318 [time-out] 60000 milliseconds
...
TID: [0] [STRATOS] [2015-06-12 18:54:51,803] INFO
{org.apache.stratos.cep.extension.FaultHandlingWindowProcessor} - Faulty
member detected [member-id]
di-000-005.di-000-005.cisco-qvpc-sf-0.domain4bcdd49a-985f-4247-a70b-31c8d65153d8
with [last time-stamp] 1434135192556 [time-out] 60000 milliseconds
...
TID: [0] [STRATOS] [2015-06-12 18:54:51,837] INFO
{org.apache.stratos.cep.extension.FaultHandlingWindowProcessor} - Faulty
member detected [member-id]
cartridge-proxy.cartridge-proxy.cartridge-proxy.domain95a58a3e-e7a9-4071-b42b-3551bad25e6a
with [last time-stamp] 1434135189149 [time-out] 60000 milliseconds
...
etc
...
TID: [0] [STRATOS] [2015-06-12 18:54:51,862] INFO
{org.apache.stratos.cep.extension.FaultHandlingWindowProcessor} - Faulty
member detected [member-id]
di-000-010.di-000-010.cisco-qvpc-sf-0.domain2ab24c1d-53cb-452e-8aa2-f02eecf2db78
with [last time-stamp] 1434135193054 [time-out] 60000 milliseconds
...
etc
...
2. The last message relating to the CPS failure is at 18:54:52. The first
message relating to recovery of the CPS is some 66 seconds later:
TID: [0] [STRATOS] [2015-06-12 18:55:58,516] INFO
{org.apache.stratos.autoscaler.rule.RuleLog} - [min-check] Partition
available, hence trying to spawn an instance to fulfil minimum count! [cluster]
cartridge-proxy.cartridge-proxy.cartridge-proxy.domain
3. However, recovery of other VMs started as much as 54 seconds before
this point to as much as 26 seconds after:
TID: [0] [STRATOS] [2015-06-12 18:55:04,564] INFO
{org.apache.stratos.autoscaler.client.CloudControllerClient} - Trying to spawn
an instance via cloud controller: [cluster]
di-000-008.di-000-008.cisco-qvpc-sf-0.domain [partition] whole-region
[network-partition-id] RegionOne
...
TID: [0] [STRATOS] [2015-06-12 18:56:20,603] INFO
{org.apache.stratos.autoscaler.client.CloudControllerClient} - Trying to spawn
an instance via cloud controller: [cluster]
di-000-007.di-000-007.cisco-qvpc-sf-0.domain [partition] whole-region
[network-partition-id] RegionOne
4. Between point 2 and 3 (with fuzz for the races), I see Stratos cleaning
the old VMs. For example:
TID: [0] [STRATOS] [2015-06-12 18:55:04,580] INFO
{org.apache.stratos.cloud.controller.iaases.JcloudsIaas} - Starting to
terminate member: [cartridge-type] cisco-qvpc-sf-0 [member-id]
di-000-008.di-000-008.cisco-qvpc-sf-0.domaina0f15eed-9599-4f3e-a70a-93ddd02ccf5f
5. However, around that point, look at this:
TID: [0] [STRATOS] [2015-06-12 18:55:12,835] INFO
{org.apache.stratos.autoscaler.rule.RuleLog} - [scale-up] Trying to scale up
over max, hence not scaling up cluster itself and
notifying to parent for possible group scaling or app
bursting.
[cluster] di-000-005.di-000-005.cisco-qvpc-sf-0.domain
[instance id]di-000-005-1 [max] 1
6. Is it possible that there is a race between the terminates and
restarts? It certainly seems so, though a detailed knowledge of Startos is
needed to confirm it:
TID: [0] [STRATOS] [2015-06-12 18:55:12,798] INFO
{org.apache.stratos.autoscaler.rule.RuleLog} - [min-check] Partition
available, hence trying to spawn an instance to fulfil minimum count! [cluster]
di-000-005.di-000-005.cisco-qvpc-sf-0.domain
TID: [0] [STRATOS] [2015-06-12 18:55:12,798] INFO
{org.apache.stratos.autoscaler.client.CloudControllerClient} - Trying to spawn
an instance via cloud controller: [cluster]
di-000-005.di-000-005.cisco-qvpc-sf-0.domain [partition] whole-region
[network-partition-id] RegionOne
TID: [0] [STRATOS] [2015-06-12 18:55:12,799] INFO
{org.apache.stratos.common.client.CloudControllerServiceClient} - Terminating
instance via cloud controller: [member]
di-000-005.di-000-005.cisco-qvpc-sf-0.domain4bcdd49a-985f-4247-a70b-31c8d65153d8
TID: [0] [STRATOS] [2015-06-12 18:55:12,812] INFO
{org.apache.stratos.cloud.controller.messaging.publisher.TopologyEventPublisher}
- Publishing member created event: [service-name] cisco-qvpc-sf-0
[cluster-id] di-000-005.di-000-005.cisco-qvpc-sf-0.domain [cluster-instance-id]
di-000-005-1 [member-id]
di-000-005.di-000-005.cisco-qvpc-sf-0.domaine9e4111c-abba-4979-af07-d13d90bbd84d
[instance-id] null [network-partition-id] RegionOne [partition-id]
whole-region [lb-cluster-id] null
TID: [0] [STRATOS] [2015-06-12 18:55:12,817] INFO
{org.apache.stratos.messaging.message.processor.topology.MemberCreatedMessageProcessor}
- Member created: [service-name] cisco-qvpc-sf-0 [cluster-id]
di-000-005.di-000-005.cisco-qvpc-sf-0.domain [member-id]
di-000-005.di-000-005.cisco-qvpc-sf-0.domaine9e4111c-abba-4979-af07-d13d90bbd84d
[cluster-instance-id] di-000-005-1
TID: [0] [STRATOS] [2015-06-12 18:55:12,834] ERROR
{org.apache.stratos.autoscaler.rule.RuleTasksDelegator} - Request in flight
threshold is Zero
TID: [0] [STRATOS] [2015-06-12 18:55:12,835] INFO
{org.apache.stratos.autoscaler.rule.RuleLog} - [scale-up] Trying to scale up
over max, hence not scaling up cluster itself and
notifying to parent for possible group scaling or app
bursting.
[cluster] di-000-005.di-000-005.cisco-qvpc-sf-0.domain
[instance id]di-000-005-1 [max] 1
(I tried to file a JIRA on this, but I’m having a bit of trouble, hence posting
here to get the ball rolling).
Thanks, Shaheed
--
Akila Ravihansa Perera
Software Engineer, WSO2
Blog: http://ravihansa3000.blogspot.com
--
Imesh Gunaratne
Senior Technical Lead, WSO2
Committer & PMC Member, Apache Stratos
--
Reka Thirunavukkarasu
Senior Software Engineer,
WSO2, Inc.:http://wso2.com,
Mobile: +94776442007<tel:%2B94776442007>
--
Reka Thirunavukkarasu
Senior Software Engineer,
WSO2, Inc.:http://wso2.com,
Mobile: +94776442007<tel:%2B94776442007>
