PI75474: SOME REQUEST RECEIVE 404 OR 503 RESPONSES WHEN INTRODUCING A NEW ODR ROUTING OR GSC RULE.

Fixes are available

APAR status

Closed as program error.

Error description

When a new ODR routing rule or ODR routing rule for a GSC is
added, a few requests flowing at that time may receive 404
or 503 responses if they match the rule.  Prior requests and
subsequent requests will be processed as expected.

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  All uses of IBM WebSphere Application       *
*                  Server On Demand Router rules               *
****************************************************************
* PROBLEM DESCRIPTION: Some requests may receive 404 or 503    *
*                      responses for a short time when         *
*                      introducing a new Routing policy HTTP   *
*                      rules or new Generic Service Cluster    *
*                      (GSC) routing policies on the On Demand *
*                      Router (ODR)                            *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
When a new ODR routing rule such as Routing policy HTTP rules or
GSC routing policies, it is possible that a few requests that
arrive at about the same time as the rule creation may match the
rule condition and receive a 404 or 503 response.  This is
because the new routing policy rule is introduced into the
system before it is completely initialized and therefore
matching requests may be incorrectly processed.  It is a very
small timing window when requests are arriving at the same time
that the rule is being added. This issue may not affect any
requests but if it does it typically only affects a small number
of requests because the window is so small.  Normal processing
will return as soon as the rule initialization is complete which
typically takes tens of milliseconds depending on the traffic
load on the ODR.

Problem conclusion

The ODR logic has been updated to remove this timing window by
ensuring that the rule initialization is complete before it is
made available to match incoming requests.

The fix for this APAR is currently targeted for inclusion in fix
pack 8.5.5.12.  Please refer to the Recommended Updates page for
delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Temporary fix

Avoid installing new routing rules such as Http Routing policies
or GSC routing policies into the On Demand Router during times
when requests are likely to be arriving that would match the
rule.  The problem is self correcting within milliseconds as the
rule processing continues and only a very small window is open
when requests could be processed incorrectly.

Comments

APAR Information

APAR number
PI75474
Reported component name
WEBS APP SERV N
Reported component ID
5724H8800
Reported release
850
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2017-01-25
Closed date
2017-01-26
Last modified date
2017-02-15

APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:

Fix information

Fixed component name
WEBS APP SERV N
Fixed component ID
5724H8800

Applicable component levels

R850 PSY
UP

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"8.5","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
04 May 2022

Tips

PI75474: SOME REQUEST RECEIVE 404 OR 503 RESPONSES WHEN INTRODUCING A NEW ODR ROUTING OR GSC RULE.

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Fix information

Fixed component name

Fixed component ID

Applicable component levels

R850 PSY

Document Information

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