Erez Zilber wrote: > open-iscsi sends nop-outs to the target. If the target responds quick > enough, we don't get a timeout. I'd like to know (for internal debug > purposes) how many times the ping timer almost expired. This sounds > like a useful feature also for other open-iscsi developers/users. > > I was thinking about adding the following mechanism: > > 1. Add an array of some length to store long nop-outs. Protect it with > some lock. > 2. If a nop-in (as a response to nop-out) was received after >= 0.7 * > ping_to (or 0.8 or whatever), add some info about it to the array > (when was the nop-out sent, how much time until we got a nop-in etc). > 3. The array should be used in a cyclic way - when it gets full, > overwrite the 1st entry. > 4. We can dump the info from the array from time to time or the user > may use iscsiadm to do that. When this is done, we can delete the > contents of the array. >
What info did you want to store? What about some perf counters for it? Add a counter for if a ping took a-b secs, b-c secs, and c-d secs. Userspace could then just get that info with the other stats. Also maybe a new iscsi_connection sysfs entry that exports the avg time to complete a nop might be nice. It might help people config the value. You also probably want to add something to reset the counters too. -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/open-iscsi?hl=.
