Storm 1.0.2 - when does Storm schedule additional workers?

[Dominik Safaric <do...@gmail.com>]

Hi everyone,

I’ve been curious about the following - under what conditions does Storm schedule additional workers of a running topology and what is its relation with the supervisor.slot.ports configuration value(s)?

Thanks in advance,
Dominik

Re: Storm 1.0.2 - when does Storm schedule additional workers?

["P. Taylor Goetz" <pt...@gmail.com>]

Hi Dominik,

Storm will not (currently) allocate additional workers to a topology unless you tell it to using the rebalance command. It will start out with the number of workers you specify with either Config.setNumWorkers() or the topology.workers configuration key.

The supervisors.slots.ports configuration controls how many worker slots are available on a given supervisor node. The default is 4 slots. So with the defaults if you have 2 supervisor nodes, you will have a total of 8 slots. All of those slots will be unused until you submit a topology (no workers running). If you submit a topology with topology.worker: 4, Storm will allocate 4 workers to the topology, and you will be left with 4 remaining open slots.

Hope this helps.

-Taylor


> On Oct 6, 2016, at 4:31 PM, Dominik Safaric <do...@gmail.com> wrote:
> 
> Hi everyone,
> 
> I’ve been curious about the following - under what conditions does Storm schedule additional workers of a running topology and what is its relation with the supervisor.slot.ports configuration value(s)?
> 
> Thanks in advance,
> Dominik