A fix is available
APAR status
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Closed as program error.
Error description
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The remote TLS application sent a TLS close alert, another TLS alert, and a FIN. AT-TLS loops trying to read the second SSL alert because every read to SSL returns with a 437, indicating the SSL connection is closed. The alert is never consumed from the TLSX control block, causing AT-TLS to schedule another attempt to read the alert because the local application has not requested TLS to be shutdown or issued it's own close. This loop will continue until the timewait timer expires and the connection is freed. Verification Steps: ip tcpipcs ttls will show 1 or more of the following: TTLS Worker Task: 7E626170 Ducb FuncCode Rcode Busy Idle Time 14D9C000 1F 1B5 FF 2010/05/12 22:23:39
Local fix
Problem summary
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**************************************************************** * USERS AFFECTED: All users of the IBM Communications Server * * for z/OS Version 1 Release(s) 10, 11, and * * 12 IP: AT-TLS * **************************************************************** * PROBLEM DESCRIPTION: TCPIP high CPU usage with AT-TLS * * enabled * **************************************************************** * RECOMMENDATION: * **************************************************************** The remote application sends a close notify alert followed by another SSL alert. The second SSL alert causes AT-TLS to schedule a read which fails with return code 437 because the SSL connection is closed. The alert is never consumed from the TLSX control block, causing AT-TLS to schedule another attempt to read the alert. +-------------------------------------------------------------+ + Please check our Communications Server for OS/390 homepages + + for common networking tips and fixes. The URL for these + + homepages can be found in Informational APAR II11334. + +-------------------------------------------------------------+
Problem conclusion
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Module EZBTLCWK has been changed to reset the connection if the application receives data after the close notify. * Cross Reference between External and Internal Names
Temporary fix
Comments
APAR Information
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APAR number
PM14615
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Reported component name
TCP/IP V3 MVS
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Reported component ID
5655HAL00
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Reported release
1A0
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Status
CLOSED PER
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PE
NoPE
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HIPER
NoHIPER
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Special Attention
NoSpecatt / Xsystem
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Submitted date
2010-05-14
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Closed date
2010-05-28
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Last modified date
2010-08-02
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APAR is sysrouted FROM one or more of the following:
-
APAR is sysrouted TO one or more of the following:
UK57452 UK57453 UK57454
Modules/Macros
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EZBTLCWK
Fix information
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Fixed component name
TCP/IP V3 MVS
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Fixed component ID
5655HAL00
Applicable component levels
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R1A0 PSY UK57452
UP10/07/09 P F007
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R1B0 PSY UK57453
UP10/07/09 P F007
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R1C0 PSY UK57454
UP10/07/09 P F007
Fix is available
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Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSSN3L","label":"z\/OS Communications Server"},"Platform":[{"code":"PF054","label":"z\/OS"}],"Version":"1A0","Line of Business":{"code":"LOB35","label":"Mainframe SW"}}]
Document Information
Modified date:
28 March 2021