does failure of write to memstore has any impact on response code from hbase

[Maneesh Bhunwal <ma...@gmail.com>]

Hi Team,

First fo all thanks for the awesome product.

Can you please help me with how will application behave when write to
memstore fails but write to WAL has succeeded already,will we return
success to the user or failure?

Also what if db crashes after writing to WAL, when db will come up after
crash, it will assume that whatever is there in WAL has been replicated,
but that may not be the case.

Can you please help me with the above?

Regards
Maneesh Bhunwal

Re: does failure of write to memstore has any impact on response code from hbase

[Stack <st...@duboce.net>]

On Mon, Aug 5, 2019 at 9:36 PM Maneesh Bhunwal <ma...@gmail.com>
wrote:

> Hi Team,
>
> First fo all thanks for the awesome product.
>
> Can you please help me with how will application behave when write to
> memstore fails but write to WAL has succeeded already,will we return
> success to the user or failure?
>
> Failure. Client will get an exception that varies dependent on failure
type.


> Also what if db crashes after writing to WAL, when db will come up after
> crash, it will assume that whatever is there in WAL has been replicated,
> but that may not be the case.
>
>
DB does not make progress until the write to the DB has been sync'd (which
means the edit has been replicated). So on crash, the WAL will be replayed.
The edit that was written to the WAL but not to the memstore on which the
client received an exception, will perpetuate.

S


> Can you please help me with the above?
>
> Regards
> Maneesh Bhunwal
>