Cache write-through for backup entries

classic Classic list List threaded Threaded
5 messages Options
Shaun Mcginnity Shaun Mcginnity
Reply | Threaded
Open this post in threaded view
|

Cache write-through for backup entries

Hi,

I would like to implement cache write through for both primary and backup entries. The use-case is to maintain a backup of the cache on disk on each DDM node. 

I have implemented CacheWriter but it is only called for primary entries, not backup entries.

Is there a way that I can implement this other that periodically polling all entries in the cache?

Regards,

Shaun
vkulichenko vkulichenko
Reply | Threaded
Open this post in threaded view
|

Re: Cache write-through for backup entries

Hi,

Store is not updated on backup nodes because Ignite assumes that the store is some kind of shared storage. Can you provide more details on your use case? How are going to use the data written to the store afterwards?

-Val
Shaun Mcginnity Shaun Mcginnity
Reply | Threaded
Open this post in threaded view
|

Re: Cache write-through for backup entries

Hi Val,

thanks for the reply.

My use-case is as follows: I have a small cache (say 100000 entries) across 3 processes. I don't have a shared backend store. If I have one primary and one backup then I can recover from a failure of 1 processes. But I can't recover from a failure of 2 processes. If I could write the cache to disk then I could recover from 2 or more processes failing, although at the risk of losing some data that was in-flight at the time of a crash.

I know it is an extreme case but it is being raised in our design discussions.

Regards,

Shaun

On Fri, Apr 1, 2016 at 10:00 PM, vkulichenko <[hidden email]> wrote:
Hi,

Store is not updated on backup nodes because Ignite assumes that the store
is some kind of shared storage. Can you provide more details on your use
case? How are going to use the data written to the store afterwards?

-Val



--
View this message in context: http://apache-ignite-users.70518.x6.nabble.com/Cache-write-through-for-backup-entries-tp3861p3872.html
Sent from the Apache Ignite Users mailing list archive at Nabble.com.

vkulichenko vkulichenko
Reply | Threaded
Open this post in threaded view
|

Re: Cache write-through for backup entries

Hi Shaun,

If the data is small, you can simply switch to replicated cache. Will this work for you?

-Val
Shaun Mcginnity Shaun Mcginnity
Reply | Threaded
Open this post in threaded view
|

Re: Cache write-through for backup entries

Hi Val,

thanks, I will give that a try.

Regards,

Shaun

On Mon, Apr 4, 2016 at 7:31 PM, vkulichenko <[hidden email]> wrote:
Hi Shaun,

If the data is small, you can simply switch to replicated cache. Will this
work for you?

-Val



--
View this message in context: http://apache-ignite-users.70518.x6.nabble.com/Cache-write-through-for-backup-entries-tp3861p3911.html
Sent from the Apache Ignite Users mailing list archive at Nabble.com.