Hi Lan, This is a good idea, but as pointed out by Andrew, there are multiple implementations composing the CoordinatorRuntime and perhaps will increase in future so this must be addressed.
Additionally, there will be changes needed in the CoordinatorRuntime Builder interface itself, for example passing a buffer size config supplier to fetch the specific config value passed by the coordinator specialization as we should not refer to config name directly in the runtime. Thanks and regards, Sushant Mahajan On Wed, 20 Aug 2025, 20:05 Andrew Schofield, < andrew_schofield_j...@outlook.com> wrote: > Hi Lan, > Thanks for the KIP. Decoupling these is a good idea. > > AS1: This is a change to the coordinator runtime and there > are two concrete implementations, the group coordinator and > the share coordinator. I think it would be equally valuable > to have `share.coordinator.append.max.buffer.size`. > The same default of 1*1024*1024 seems appropriate to me. > > Thanks, > Andrew > ________________________________________ > From: Lan Ding <isdin...@163.com> > Sent: 20 August 2025 14:57 > To: dev@kafka.apache.org <dev@kafka.apache.org> > Subject: Re: [DISCUSS] KIP-1196: Introduce > group.coordinator.append.max.bytes config > > Hi Chia-Ping, > > > > Thanks for the feedback. The original configuration name was potentially > ambiguous; > > it has therefore been renamed to > `group.coordinator.append.max.buffer.size`. > > > > chia_00: > > Update the vaild values of group.coordinator.append.max.buffer.size to be > > less than message.max.bytes. > > > > chia_01: > > Yes, I agree. Make this config to be updated dynamically. > > > > chia_02: > > I agree with you. Since the buffer behavior is a soft limit, this change > should > > not impact any existing functionality or require special compatibility > measures. > > > > Best, > > Lan > > > > > At 2025-08-18 00:54:15, "Chia-Ping Tsai" <chia7...@gmail.com> wrote: > >hi Lan > > > >chia_00: > > > >The `group.coordinator.append.max.bytes` must be smaller than the max > >message size; Otherwise, it could generate an invalid record > > > >chia_01: > > > >Since the max message size is a dynamic configuration, should we also make > >`group.coordinator.append.max.bytes` dynamic? > > > >chia_02: > > > >Is compatibility necessary? The max buffer of the new coordinator is > >currently transparent to users, so I don't think there are any users > >explicitly setting the max message size to control the buffer used by the > >new coordinator > > > >Best, > >Chia-Ping > > > > > >Lan Ding <isdin...@163.com> 於 2025年8月18日 週一 上午12:37寫道： > > > >> Hello everyone, I'd like to discuss a KIP regarding introducing a new > >> configuration, > >> group.coordinator.append.max.bytes Thank you! KIP link: > >> https://cwiki.apache.org/confluence/x/hA5JFg Best, Lan Ding >
