Skip to main content
NetApp Knowledge Base

What's cf_hwassist_missedKeepAlive timeout and tolerant period?

  1. Last updated
  2. Save as PDF
Views:
2,131
Visibility:
Public
Votes:
1
Category:
fas-systems
Specialty:
HW
Last Updated:

Applies to

  • NetApp AFF and FAS systems
  • ONTAP 9

Answer

  • cf_hwassist_missedKeepAlive incident is recorded in EMS after 60 seconds, after a hw-assist packet sent
  • The hw-assist packets are sent by UDP every 180 seconds:
    •  There is no retransmission of packets if the packets are sent and not received
    • If a UDP packet is dropped, blocked, wedged, redirected, etc.. and a node doesn't receive it, the node will just wait for 180 seconds, until the next packet is sent
  • So if a cf_hwassist_recvKeepAlive event is showing within 120 seconds after cf_hwassist_missedKeepAlive, it can be ignored safely

[Nodename-02: cf_hwassist: cf.hwassist.missedKeepAlive:debug]: HW-assisted takeover missing keep-alive messages from HA partner (Nodename-01).
[Nodename-02: cf_hwassist: cf.hwassist.recvKeepAlive:debug]: hw_assist: Received hw_assist KeepAlive alert from partner(Nodename-01).

Additional Information

  • For the cause of cf_hwassist_missedKeepAlive, because hw-assist configured and transmit with IP and port on e0M which goes through customer network environment, nearly every instance of this type of failure, is due to network dropped packets.
  • Check the hwassist-health-check-interval by command

aff200-2n-dal-1::> storage failover show -fields hwassist,hwassist-partner-ip,hwassist-partner-port,hwassist-health-check-interval,hwassist-retry-count,hwassist-status
node          hwassist hwassist-partner-ip hwassist-partner-port hwassist-health-check-interval hwassist-retry-count hwassist-status
------------- -------- ------------------- --------------------- ------------------------------ -------------------- ---------------
aff200-dal-1a true     10.128.227.184      4444                  180                            2                    active
aff200-dal-1b true     10.128.227.183      4444                  180                            2                    active
2 entries were displayed.

 

NetApp provides no representations or warranties regarding the accuracy or reliability or serviceability of any information or recommendations provided in this publication or with respect to any results that may be obtained by the use of the information or observance of any recommendations provided herein. The information in this document is distributed AS IS and the use of this information or the implementation of any recommendations or techniques herein is a customer's responsibility and depends on the customer's ability to evaluate and integrate them into the customer's operational environment. This document and the information contained herein may be used solely in connection with the NetApp products discussed in this document.