High CPU due to large number of volume-list-info zapi calls

Applies to

• ONTAP 9.x
• CPU utilization
• volume-list-info ZAPI (Zephyr API)

Issue

• High CPU across all nodes and Exempt Domain is 1000+%
• Multiple volume-get-iter zapi calls are seen under APACHE-ACCESS.GZ log:

<client_ip> <cluster_ip> 4294967295 <user> [date] "POST /servlets/netapp.servlets.admin.XMLrequest_filer HTTP/1.1" 200 1569200 11993904 - 0 + volume-get-iter

• Held connections are seen in APACHE-ERROR.GZ log

[date] [mpm_event:notice] [pid x:tid x] Holding a connection from ipspace ID -1, remote address <client_ip> while 119 others are held and 80 are active

[date] [mpm_event:notice] [pid x:tid x] A keepalive connection from ipspace ID -1, remote address <client_ip> is being suspended between requests while the 80-connection limit has been reached. (80 active, 120 waiting) Clients should limit the number of concurrent keepalive connections to avoid large performance penalties and/or failures.