I vaguely recall discussing this a while ago. I'm in favor of this idea. On Mon, Aug 17, 2026 at 3:04 AM Štefan Miklošovič <[email protected]> wrote:
> There is a ticket for this (1) and discussion nobody answered to (2). > > Is there any reason why we are compressing with lz4 only? For inter-dc > communication where dc's are in geographically distant areas etc. I > think that compressing it with zstd instead of lz4 would be an option > as well as it would, presumably, transfer less data. I know there are > caveats attached to that like (likely) increased CPU when > de/compressing with it, especially when zstd compression levels would > be higher than default etc. but otherwise this is worthy of giving it > a shot? This is something people would need to opt into, of course, > but zstd seems like a good compression algo to add for this stuff, > especially when we declare (3) that we get the best compression ratio > (better than lz4) at the expense of slightly worse de/compression > times (which are tunable based on compression levels). If a traffic > goes from Europe to Asia and it costs dozens of milliseconds then it > is basically irrelevant if we add a few more while we compress it 30% > less than lz4, also when inter-continental / inter-cloud traffic is > paid for based on volume or similar. > > I have a working prototype locally where I can configure what the > internode will be compressed with, I just want to check with ML this > is something we might eventually consider adding so I can measure the > performance and similar more deeply. > > (1) https://issues.apache.org/jira/browse/CASSANDRA-20488 > (2) https://lists.apache.org/thread/dzjd3kqtwb8bncsfs36msbfv8v4kgfyy > (3) > https://cassandra.apache.org/doc/latest/cassandra/managing/operating/compression.html >
