A fix is available
APAR status
Closed as program error.
Error description
After heavy outbound traffic out the VSWITCH UPLINK port, guests lose connectivity until the VSWITCH RDEV connection is reset. VSWITCH guest connectivity is not affected. Resetting the guest interface does not restore connectivity. VSWITCH disconnect and connect sequence (or VSWITCH FAILOVER) will restore guest connectivity.
Local fix
Reset the uplink connection with the SET VSWITCH command until this PTF is available.
Problem summary
**************************************************************** * USERS AFFECTED: VSWITCH users may experience connectivity * * loss after spikes in outbound traffic * * through the UPLINK port. * **************************************************************** * PROBLEM DESCRIPTION: * **************************************************************** * RECOMMENDATION: APPLY PTF * **************************************************************** If a spike in outbound VSWITCH traffic causes the pending queue for the UPLINK port to overflow, the logic to discard those messages fails to operate correctly (leaving the messages in place to accumulate). New outbound messages encounter the same error, so coupled guests are no longer able to transmit to an external host. The queue can be cleared by a failover, or by a VSWITCH disconnect and connect sequence. This allows the affected hosts to restore communication across the uplink port.
Problem conclusion
Entry point HCPSWASP directs outbound messages to the UPLINK interface. It includes logic to detect an overflow of messages pending for that UPLINK port. When too many messages are in that queue, an error in the register specification causes CP to clear the queue from the source device extension instead of the destination (UPLINK) device extension block. That error is corrected with this update, so the UPLINK device queue is properly cleared and prepared to handle subsequent outbound network messages. This allows the affected hosts to process new outbound network messages. The guests should automatically recover from the overflow (for example, the TCP/IP protocol will retransmit as necessary).
Temporary fix
FOR RELEASE VM/ESA CP/ESA R640 : PREREQ: VM66037 CO-REQ: NONE IF-REQ: NONE
Comments
APAR Information
APAR number
VM66093
Reported component name
VM CP
Reported component ID
568411202
Reported release
A64
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2017-11-18
Closed date
2017-11-29
Last modified date
2018-04-24
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UM35249
Modules/Macros
HCPSWA
Fix information
Fixed component name
VM CP
Fixed component ID
568411202
Applicable component levels
R540 PSN
UP
R630 PSN
UP
R640 PSY UM35249
UP18/04/24 P 1801 ¢
Fix is available
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.
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Document Information
Modified date:
24 April 2018