Is there any chance the bootstrapping lost data?

[Jinhua Luo <lu...@gmail.com>]

Hi All,

While the pending node get streaming of token ranges from other nodes,
all coordinator would send new writes to it so that it would not miss
any new data, correct?

I have two (maybe silly) questions here:
Given the CL is ONE,
a) what if the coordinator haven't meet the pending node via gossip,
and only sends mutation to the main replica (the replica would be
replaced by the pending node)?
b) what if the coordinator fails to send the mutation to pending node?

In both cases, when the pending node finish streaming and join the
ring eventually, the mutation mentioned above would be lost?

Regards,
Jinhua Luo

---------------------------------------------------------------------
To unsubscribe, e-mail: user-unsubscribe@cassandra.apache.org
For additional commands, e-mail: user-help@cassandra.apache.org

Re: Is there any chance the bootstrapping lost data?

[Jeff Jirsa <jj...@gmail.com>]

> On Dec 28, 2018, at 2:17 AM, Jinhua Luo <lu...@gmail.com> wrote:
> 
> Hi All,
> 
> While the pending node get streaming of token ranges from other nodes,
> all coordinator would send new writes to it so that it would not miss
> any new data, correct?
> 
> I have two (maybe silly) questions here:
> Given the CL is ONE,
> a) what if the coordinator haven't meet the pending node via gossip,
> and only sends mutation to the main replica (the replica would be
> replaced by the pending node)?

There’s a delay between joining in gossip and calculating the bootstrap streaming plan to mitigate this 

There’s also protections added in recent versions to avoid ack’ing a write (or read or stream) for ranges that don’t properly own the range, so topology/gossip disagreements shouldn’t result in consistency violations. 

> b) what if the coordinator fails to send the mutation to pending node?

The coordinators increase consistency level/ blockFor by one for each pending node, so the pending node may not get the write if your RF is > 1, but enough nodes will that you’ll meet your consistency guarantee

> 
> In both cases, when the pending node finish streaming and join the
> ring eventually, the mutation mentioned above would be lost?
> 
> Regards,
> Jinhua Luo
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: user-unsubscribe@cassandra.apache.org
> For additional commands, e-mail: user-help@cassandra.apache.org
> 

---------------------------------------------------------------------
To unsubscribe, e-mail: user-unsubscribe@cassandra.apache.org
For additional commands, e-mail: user-help@cassandra.apache.org