Thanks Patick! > Giving it a minute between and waiting until each node enters BOOTSTRAP/STREAMING are good signs to proceed with the next one. This is great to know!
> When adding nodes to each rack, you just have to worry about the source node for streaming Right — I’ve been keeping that in mind and making sure new nodes are added in a way that avoids having the same source node stream to multiple new nodes simultaneously. > Add nodes across each rack at the same time, vs all in one rack at a time. The source for streaming is where it matters and this will ensure it's spread out. Thanks for confirming this! On Fri, Dec 12, 2025 at 1:52 PM Patrick McFadin <[email protected]> wrote: > Hi Long, > > I'm sure you'll get some debate on if one token range per node is ideal or > not, but technically it will work just fine. You are responsible for the > range management, but that's your question about overlap. When you need to > scale, getting the ranges right will be a manual process. > > Your point on starting up. Giving it a minute between and waiting until > each node enters BOOTSTRAP/STREAMING are good signs to proceed with the > next one. > > When adding nodes to each rack, you just have to worry about the source > node for streaming. It could create a hotspot you weren't expecting. Add > nodes across each rack at the same time, vs all in one rack at a time. The > source for streaming is where it matters and this will ensure it's spread > out. > > -Dcassandra.consistent.simultaneousmoves.allow=true is a good idea. If > you have the bandwidth then definately consider upping > stream_throughput_outbound_megabits_per_sec[1] > > Patrick > > 1- > https://cassandra.apache.org/doc/4.1/cassandra/configuration/cass_yaml_file.html#stream_throughput_outbound_megabits_per_sec > > On Wed, Dec 10, 2025 at 10:24 PM Long Pan <[email protected]> wrote: > >> Hi Cassandra Community, >> >> I’m on Cassandra *4.1.10*, and I’ve been experimenting with the *single-token >> setup* (num_tokens = 1, with tokens manually assigned per node). >> >> When *concurrently* adding multiple nodes to a cluster, I make sure >> their bootstrap token ranges do not overlap. Is there anything else I >> should be aware of? >> >> More specifically: >> >> 1. >> >> *Is it good to start multiple new nodes at the exact same time*, as >> long as their affected token ranges do not overlap? >> Or is some sequencing still recommended (e.g., don’t start node B >> until node A has *entered* streaming)? >> 2. >> >> *Is it better to complete node additions rack-by-rack*, or does rack >> distribution not matter as long as the token ranges affected by the new >> nodes don’t overlap? My understanding is that rack distribution does not >> matter. >> 3. >> >> For large clusters (many nodes and large data volumes), what *Cassandra >> parameters or JVM options* are important for successfully adding >> multiple nodes simultaneously, beyond enabling >> -Dcassandra.consistent.simultaneousmoves.allow=true >> and using num_tokens=1? >> >> Are settings like *ring_delay_ms* or the various *streaming >> throughput–related parameters* also important in practice? I suspect >> they matter quite a bit, but I want to confirm. >> >> Thank you so much for your help! >> >> Best, >> Long >> >
