topic Re: Maintenance: Restarting Servers in Windchill

Maintenance: Restarting Servers

Darquise — Wed, 02 May 2018 13:44:55 GMT

Is there a recommendation as to how often the Windchill and database servers should be restarted?Should they be restarted monthly? Is there an order as to which server should be restarted first?

Re: Maintenance: Restarting Servers

ChrisSpartz — Fri, 09 May 2014 17:11:23 GMT

There's no official recommendation from PTC about how often to restart the servers. Theoretically, they shouldn't ever need to be restarted, unless you make a configuration change that requires a restart. Though, in practice, that may not be the case.

As to the order of restarting, the DB needs to be available in order for Windchill to start up. So, the DB will need to be restarted first.

Re: Maintenance: Restarting Servers

jessh — Fri, 09 May 2014 18:28:30 GMT

LDAP should be up when Windchill is started as well.

Essentially the back-end datastores should be up first.

Re: Maintenance: Restarting Servers

Darquise — Mon, 12 May 2014 15:14:48 GMT

Thank you for your responses...

I find that approx every 25-30 days I get a "Memory usage threshold exceeded" notification and then Windchill slows right down and is unresponsive. so I restart the server, hence why I wanted to setup a monthly scheduled server restart.

How do you fix this error or clear memory usage without restarting the server?

Re: Maintenance: Restarting Servers

jessh — Mon, 12 May 2014 15:51:25 GMT

This suggests a slow memory leak. What type of memory threshold was exceeded? Heap or perm gen?

If the threshold was perm gen, then it is possible that the perm gen allocation should simply be increased -- and that it takes 25-30 days simply to make use of enough different features/capabilities to load that many classes. It may, however, be a slow leak, but this sort of issue is very hard to track down. One note in this regard, if using CMS garbage collection, be sure to use the necessary arguments to force this to include perm gen collection (which is unfortunately not the default with CMS garbage collection).

If this is not a perm gen issue, however, then it is most likely a slow memory leak. The only way to get a good idea as to the cause is to grab a heap dump and then analyze this -- or, more likely, have PTC analyze this.

Re: Maintenance: Restarting Servers

Darquise — Thu, 15 May 2014 15:31:30 GMT

Here is the notification that I received:

Memory usage threshold exceeded

Class:

class javax.management.Notification

Message:

Memory usage exceeds collection usage threshold

SequenceNumber:

Source (Direct):

com.ptc:wt.subsystem=Monitors,wt.monitorType=Memory

Source (Original):

java.lang:type=Memory

TimeStamp:

2014-05-08 19:30:06.340 +0000 [1399577406340]

Type:

java.management.memory.collection.threshold.exceeded

UserData:

count

poolName

PS Old Gen

usage

committed	2859139072
init	2859139072
max	2859139072
used	2859139072

JVM Name:

3920@ACM

Threshold Info:

PermGenPercentCollUsage	84.45762062072754
PermGenPercentCollUsageThreshold	95.0
HeapPercentUsage	87.16486411932526
MinAvailableHeapPercThreshold	0.0
CheckIntervalSeconds	30
PermGenPercentUsagePeak	87.18524169921875
PermGenPercentUsage	84.46382713317871
MinAvailableHeapThreshold	0
PermGenPercentUsageThreshold	97.5
OldGenPercentUsage	100.0
GCBaitingEnabled	false
OldGenPercentCollUsageThreshold	95.0
OldGenPercentUsageThreshold	0.0
HeapPercentUsageThreshold	0.0
OldGenPercentUsagePeak	100.0
NoisyStillExceededNotifications	false
OldGenPercentCollUsage	100.0

Memory Data:

Verbose

true

ObjectPendingFinalizationCount

NonHeapMemoryUsage

committed	404815872
init	195493888
max	469762048
used	404218584

HeapMemoryUsage

committed	3812163584
init	4288675840
max	3812163584
used	3322858904

Memory Pool Data:

java.lang:type=MemoryPool,name=Code Cache

CollectionUsageThresholdSupported

false

UsageThresholdExceeded

true

PeakUsage

committed	50331648
init	2555904
max	50331648
used	49951616

Type

NON_HEAP

Usage

committed	50331648
init	2555904
max	50331648
used	49951616

UsageThresholdCount

Name

Code Cache

UsageThreshold

UsageThresholdSupported

true

MemoryManagerNames

CodeCacheManager

CollectionUsage

Valid

true

java.lang:type=MemoryPool,name=PS Eden Space

CollectionUsageThresholdSupported

true

CollectionUsageThresholdExceeded

true

CollectionUsageThresholdCount

PeakUsage

committed	1428094976
init	1072234496
max	1428094976
used	1428094976

Type

HEAP

Usage

committed	476512256
init	1072234496
max	476512256
used	464485688

Name

PS Eden Space

UsageThresholdSupported

false

MemoryManagerNames

PS MarkSweep

PS Scavenge

CollectionUsage

committed	476512256
init	1072234496
max	476512256
used	458467824

Valid

true

CollectionUsageThreshold

java.lang:type=MemoryPool,name=PS Old Gen

CollectionUsageThresholdSupported

true

CollectionUsageThresholdExceeded

true

CollectionUsageThresholdCount

UsageThresholdExceeded

true

PeakUsage

committed	2859139072
init	2859139072
max	2859139072
used	2859139072

Type

HEAP

Usage

committed	2859139072
init	2859139072
max	2859139072
used	2859139072

UsageThresholdCount

Name

PS Old Gen

UsageThreshold

UsageThresholdSupported

true

MemoryManagerNames

PS MarkSweep

CollectionUsage

committed	2859139072
init	2859139072
max	2859139072
used	2859139072

Valid

true

CollectionUsageThreshold

2716182118

java.lang:type=MemoryPool,name=PS Perm Gen

CollectionUsageThresholdSupported

true

CollectionUsageThresholdExceeded

false

CollectionUsageThresholdCount

UsageThresholdExceeded

false

PeakUsage

committed	369360896
init	192937984
max	419430400
used	365681408

Type

NON_HEAP

Usage

committed	354484224
init	192937984
max	419430400
used	354273576

UsageThresholdCount

Name

PS Perm Gen

UsageThreshold

408944640

UsageThresholdSupported

true

MemoryManagerNames

PS MarkSweep

CollectionUsage

committed	354484224
init	192937984
max	419430400
used	354240936

Valid

true

CollectionUsageThreshold

398458880

java.lang:type=MemoryPool,name=PS Survivor Space

CollectionUsageThresholdSupported

true

CollectionUsageThresholdExceeded

true

CollectionUsageThresholdCount

PeakUsage

committed	476512256
init	178651136
max	476512256
used	476491120

Type

HEAP

Usage

committed	476512256
init	178651136
max	476512256
used	0

Name

PS Survivor Space

UsageThresholdSupported

false

MemoryManagerNames

PS MarkSweep

PS Scavenge

CollectionUsage

committed	476512256
init	178651136
max	476512256
used	0

Valid

true

CollectionUsageThreshold

Re: Maintenance: Restarting Servers

jessh — Thu, 15 May 2014 15:55:52 GMT

So with 100% of old generation used after garbage collection and 87.16% of overall heap being used, that's not looking particularly good. Was the system idle at the time? If so, then that's even worse.

As for what's filling all that memory, really only a heap dump can tell in detail. A heap histogram might give some clues, though.