A fix is available
APAR status
Closed as program error.
Error description
Abendsxa004 sxa004 occurs processing a large number of UDP packets being sent to the physical network.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All customers using a z/VM VSwitch with a * * Link Aggregation Port Group configuration. * **************************************************************** * PROBLEM DESCRIPTION: * **************************************************************** * RECOMMENDATION: APPLY PTF * **************************************************************** A VSwitch configured with a Link Aggregated (LAG) UpLink Port may encounter a SXA004 ABEND when moving workload around within the LAG. This may occur if one or more guests are transmitting a very large number of UDP Packets to the external network at the same time z/VM is performing LACP Marker Processing to move workload around. Marker Processing requires the VSwitch to buffer out going packets to a specific OSA Port, until a Marker Response is returned from the connected physical partner switch. If the physical switch is slow to respond and one or more guests continually transmit a large number of packets for z/VM to buffer, it's possible we can exhaust all storage in the system execution space with NDMBK Blocks queued for transmission to the external network.
Problem conclusion
VSwitch Marker Processing is enhanced to take the appropriate action to limit the number of NDMBKs queued on the Stage I and II Suspension Queues. A new High Capacity Time-Out is added to the existing Marker Time-Out support. Its purpose is to slow up a suspended high capacity guest when a low limit threshold is reached and terminate Marker Processing when a high limit threshold is hit. The action taken depends on the current count of NDMBKs and the time they are on the suspension queue.
Temporary fix
********* * HIPER * ********* FOR RELEASE VM/ESA CP/ESA R540 : PREREQ: VM65672 CO-REQ: NONE IF-REQ: NONE FOR RELEASE VM/ESA CP/ESA R630 : PREREQ: VM65583 CO-REQ: NONE IF-REQ: NONE FOR RELEASE VM/ESA CP/ESA R640 : PREREQ: NONE CO-REQ: NONE IF-REQ: NONE
Comments
APAR Information
APAR number
VM66037
Reported component name
VM CP
Reported component ID
568411202
Reported release
630
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2017-06-15
Closed date
2017-07-24
Last modified date
2017-11-24
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UM35176 UM35177 UM35178
Modules/Macros
HCPSWA
Fix information
Fixed component name
VM CP
Fixed component ID
568411202
Applicable component levels
R540 PSY UM35176
UP17/07/25 I 1000 ¢
R630 PSY UM35177
UP17/07/25 I 1000 ¢
R640 PSY UM35178
UP17/07/25 P 1702 ¢
Fix is available
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Document Information
Modified date:
24 November 2017