different results on UI using stats sample rate parameter
397 views
Skip to first unread message
Corne
unread,
Apr 18, 2012, 10:11:23 PM4/18/12
Reply to author
Sign in to reply to author
Forward
Sign in to forward
Delete
You do not have permission to delete messages in this group
Copy link
Report message
Show original message
Either email addresses are anonymous for this group or you need the view member email addresses permission to view the original message
to storm-user
Hi
I ran a topology into a cluster and I made some tests setting the
"stats sample rate" parameter to 1 and I could see that the final
number of acked of the bolt is fine (lets say 1 million), so I made
the exact same test setting the parameter to 0.05 and the final number
of acked is less than the number I was expecting (1 million) or
sometimes it is grater, however I write my results into a log and I
can see that the actual number of tuples processed was 1 million (the
expected one), so :
is this an UI related issue?
Or do you know why is this happening?
Thanks
Nathan Marz
unread,
Apr 19, 2012, 7:04:32 PM4/19/12
Reply to author
Sign in to reply to author
Forward
Sign in to forward
Delete
You do not have permission to delete messages in this group
Copy link
Report message
Show original message
Either email addresses are anonymous for this group or you need the view member email addresses permission to view the original message
to storm...@googlegroups.com
It's likely a UI-related issue. How much over/under 1 million are you seeing the numbers?
You do not have permission to delete messages in this group
Copy link
Report message
Show original message
Either email addresses are anonymous for this group or you need the view member email addresses permission to view the original message
to storm...@googlegroups.com
OK, that's just the result of the fact that it's sampling. The way it works is that if you choose a sampling rate of 0.05, it will pick a random element of the next 20 events in which to increase the count by 20. So if you have 20 tasks for that bolt, your stats could be off by +-380.
Cornelio Iñigo
unread,
Apr 19, 2012, 7:52:39 PM4/19/12
Reply to author
Sign in to reply to author
Forward
Sign in to forward
Delete
You do not have permission to delete messages in this group
Copy link
Report message
Show original message
Either email addresses are anonymous for this group or you need the view member email addresses permission to view the original message