PM07820: WHEN DISTRIBUTING TRANSACTIONS USING WEB SERVICES ATOMIC TRANSACTIONS, DEADLOCK MAY OCCUR.

Fixes are available

APAR status

Closed as program error.

Error description

Customer is developing a distributed system that communicates
by Web Services and has troubles with distributed transactions
on a WebSphere Application Server cluster. Some of web services
calls have to run under a global transaction. Using
WS-AtomicTransaction and it works fine for most situations
except for the following problem:
Several operations work with the same data in the backend Oracle
transactions. It means that operations insert and update data in
the same database table. For example one method inserts a new
row to the table. The second method updates this inserted row.
Third operation updates another data for this row and so on...
All under global transaction so if anything is wrong in
processing all changes under the global transaction it rolls
back.Up to now it is fine.
BUT:
We scaled the application servers and we have a cluster of
WebSphere Application Servers. Web Services are called through
IBM HTTP Server and WebSphere plugin load balances Web Services
calls. If a sequence of Web Services operations is targeted to
one cluster member it works fine as written above. But if the
operations are targeted to more cluster members the
transaction branches in Oracle are not tightly coupled in
that case and the reason is: the operations cannot see any
change of other operations under the global transaction.

Local fix

Will be fix in current customer's release

Problem summary

****************************************************************
* USERS AFFECTED:  All IBM WebSphere Application Server V6.1   *
*                  and V7.0 users of Web Services Atomic       *
*                  Transactions ( WS-AT ).                     *
****************************************************************
* PROBLEM DESCRIPTION: When distributing transactions using    *
*                      WS-AT, database conflicts may occur.    *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
When a distributed system that communicates by Web Services
(using WS-AT to coordinate resources) tries to update the same
database from multiple servers, the transaction branches are
not viewed as tightly coupled by Oracle (tm), and so various
data base conflicts may occur - for example updates seen in
one branch cannot be seen in other branches or deadlocks may
occur.

The root cause of this is that when the transaction is
distributed to another server, the global id is not preserved
by the WS-AT service.

Problem conclusion

In order to allow Oracle to handle multiple transaction
branches as tightly-coupled, a change has been made to the
WS-AT service to allow the global id to be preserved when the
transaction is distributed.

This fix requires a Transaction Service Custom Property to be
defined on each server to enable the new behavior:

For each server that will participate in the distributed
transaction:

1. Login to the Administrative Console
2. Select Servers -> Application Servers -> server ->
Container Services -> Transaction Service
3. Select the Configuration tab
4. Select Custom Properties
5. Press new
6. Enter PRESERVE_GTID_OVER_WSAT as the name, and true as the
value
7. Click Ok
8. Save changes
9. Restart the server

The fix for this APAR is currently targeted for inclusion in
fix packs 6.1.0.33 and 7.0.0.11.  Please refer to the
Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Temporary fix

Comments

APAR Information

APAR number
PM07820
Reported component name
WEBS APP SERV N
Reported component ID
5724H8800
Reported release
61I
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-02-17
Closed date
2010-03-22
Last modified date
2010-03-22

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

R61A PSY
UP
R61H PSY
UP
R61I PSY
UP
R61P PSY
UP
R61S PSY
UP
R61W PSY
UP
R61Z PSY
UP
R700 PSY
UP

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
24 October 2021

Tips

PM07820: WHEN DISTRIBUTING TRANSACTIONS USING WEB SERVICES ATOMIC TRANSACTIONS, DEADLOCK MAY OCCUR.

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

R61A PSY

R61H PSY

R61I PSY

R61P PSY

R61S PSY

R61W PSY

R61Z PSY

R700 PSY

Document Information

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