Hi Kenneth, The concern is that in some cases, hints accumulate on nodes, and it takes a while until they are delivered (multi DCs). I see that whenever there are a lot of hints in play,like after a rolling restart, the cluster works harder. That's why I want to decrease the hints delivery time. I didn't want to change the configuration blindly and thought the community might have some experience on this subject.
I went over the cassandra.yaml file but didn't find any information on optimizing these attributes, just that the max_throttle is divided between nodes in the cluster and that I should increase the max_hints_delivery_threads because I have multi-dc deployments. # Maximum throttle in KBs per second, per delivery thread. This will be # reduced proportionally to the number of nodes in the cluster. (If there # are two nodes in the cluster, each delivery thread will use the maximum # rate; if there are three, each will throttle to half of the maximum, # since we expect two nodes to be delivering hints simultaneously.) hinted_handoff_throttle_in_kb: 1024 # Number of threads with which to deliver hints; # Consider increasing this number when you have multi-dc deployments, since # cross-dc handoff tends to be slower max_hints_delivery_threads: 2 Thanks for your help! On Mon, Mar 4, 2019 at 6:44 PM Kenneth Brotman <kenbrot...@yahoo.com.invalid> wrote: > What is the concern? Why are you looking there? The casssandra.yml file > has some notes about it. Did you read them? > > > > *From:* shalom sagges [mailto:shalomsag...@gmail.com] > *Sent:* Monday, March 04, 2019 7:22 AM > *To:* user@cassandra.apache.org > *Subject:* A Question About Hints > > > > Hi All, > > > > Does anyone know what is the most optimal hints configuration (multiple > DCs) in terms of > > max_hints_delivery_threads and hinted_handoff_throttle_in_kb? > > If it's different for various use cases, is there a rule of thumb I can > work with? > > > > I found this post but it's quite old: > > http://www.uberobert.com/bandwidth-cassandra-hinted-handoff/ > > > > Thanks! >
