Re: Cassandra Collections performance issue

ailto:user@cassandra.apache.org>> Cc: "Peddi, Praveen" <pe...@amazon.com<mailto:pe...@amazon.com>> Subject: Re: Cassandra Collections performance issue I think the key to your problem might be around "we overwrite every value". You are creating a large numb

Re: Cassandra Collections performance issue

I have experienced excessive performance issues while using collections as well. Mostly my issue was due to the excessive number of cells per partition that having a modest map size requires. Since you are reading and writing the entire map, you can probably gain some performance the same way I

Re: Cassandra Collections performance issue

Just to help other users reading along here, what is your access pattern with maps? I mean, do you typically have a large or small number of keys set, are you typically mostly adding keys or deleting keys a lot, adding one at a time or adding and deleting a lot in a single request, or... what? And

Re: Cassandra Collections performance issue

If the overwrites are per map key there are no tombstones generated; only if the whole map is re-imaged are tombstones created, and prior to 3.0 this indeed can be major problem if done frequently. Prior to 3.0 collections also forbid certain optimisations to cell comparisons, and as a result can

Re: Cassandra Collections performance issue

I think the key to your problem might be around "we overwrite every value". You are creating a large number of tombstones, forcing many reads to pull current results. You would do well to rethink why you are having to to overwrite values all the time under the same key. You would be better to

Re: Cassandra Collections performance issue

Hello all, Recently we added one of the table fields from as Map in Cassandra 2.1.11. Currently we read every field from Map and overwrite map values. Map is of size 3. We saw that writes are 30-40% slower while reads are 70-80% slower. Please find below some metrics that can help.

Re: Cassandra Collections performance issue

On Mon, Feb 8, 2016 at 2:10 PM, Agrawal, Pratik wrote: > Recently we added one of the table fields from as Map in > *Cassandra > 2.1.11*. Currently we read every field from Map and overwrite map values. > Map is of size 3. We saw that writes are 30-40% slower