NMSDK & Python, bringing a filer to its knees

BENJAMIN_SERVOZ — Thu, 05 Jun 2025 06:37:48 GMT

We've been tracing down for weeks the cause of a serious performance decline of our filer. We have narrowed it down to a python script using the latest NMSDK.

Symptoms:

- Sustained high CPU that persist after the NMSDK calls

- NFS RPC call take up to 20 times longer, affecting user experience

- we have no visibility of memory but a reboot alleviates the issue. So does a cluster takes over.

Method for reproduction:

Make a call for nfs-exportfs-modify-rule-2 using an NaElement previously retrieved via a call for nfs-exportfs-list-rules-2.

In order to modify the export ruleset, we retrieve a list with by calling nfs-exportfs-list-rules-2 and build upon it.

Notes on reproduction:

- Creating an nfs-exportfs-modify-rule-2 from scratch does not reproduce the issue, an NaElement from a previous nfs-exportfs-list-rules-2 needs to be used

- The new ruleset being applied with the nfs-exportfs-modify-rule-2 call needs to be different from the existing ruleset.

Code for reproduction: (see attached file)

- edit netapp.py

- update line 11 to point to a filer

- update line 13 with the proper credentials

- launch ./test.py

topic NMSDK & Python, bringing a filer to its knees in Software Development Kit (SDK) and API Discussions

NMSDK & Python, bringing a filer to its knees