# Store & Forward Buffer cannot be emptied

**URL:** <https://forum.inductiveautomation.com/t/store-forward-buffer-cannot-be-emptied/17823>\
**Category:** Ignition\
**Created:** [April 24, 2018, 9:13pm UTC](https://forum.inductiveautomation.com/t/store-forward-buffer-cannot-be-emptied/17823 "2018-04-24T21:13:59Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Ivan\_a](https://avatars.discourse-cdn.com/v4/letter/i/9f8e36/32.png) [@Ivan\_a](https://forum.inductiveautomation.com/u/Ivan_a)\
**Post date:** [April 24, 2018, 9:13pm UTC](https://forum.inductiveautomation.com/t/store-forward-buffer-cannot-be-emptied/17823/1 "2018-04-24T21:13:59Z")

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We have a redundant ignition with local MySQL DB running on VMWare VMs. about 20k tags.  
Everyday the store & forward starts to fill up at some time, and never completely empties.  
We use tag historian for almost all tags.  
We tried several configuration of write times and sizes as recommended., but we are are able to empty the local cache.  
The hardware has plenty of RAM and CPU, so that doesn’t seems to be the issue.  
I have noticed some clockdrift messages. Can this be related?

Thanks

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [April 24, 2018, 9:42pm UTC](https://forum.inductiveautomation.com/t/store-forward-buffer-cannot-be-emptied/17823/2 "2018-04-24T21:42:13Z")

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What has been done to tune your Ignition install and tune your MySQL install? I would not expect the settings out of the box to be suited to 20k tags, especially if the DB and GW are on the same machine.

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**Author:** ![Ivan\_a](https://avatars.discourse-cdn.com/v4/letter/i/9f8e36/32.png) [@Ivan\_a](https://forum.inductiveautomation.com/u/Ivan_a)\
**Post date:** [April 24, 2018, 9:44pm UTC](https://forum.inductiveautomation.com/t/store-forward-buffer-cannot-be-emptied/17823/3 "2018-04-24T21:44:31Z")

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Nothing specific I guess. What are your recommendations? Shall we put DB on a separate VM?

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [April 24, 2018, 9:47pm UTC](https://forum.inductiveautomation.com/t/store-forward-buffer-cannot-be-emptied/17823/4 "2018-04-24T21:47:47Z")

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> [@Ivan\_a](#):
>
> Shall we put DB on a separate VM?

Highly recommended. And peruse the MySQL docs for tuning. As for Ignition, you need to edit ignition.conf to use an appropriate amount of memory, and I also suggest using G1GC. See [this thread](http://forum.inductiveautomation.com/t/gateway-java-question-7-7-2/10402).

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**Author:** ![Ivan\_a](https://avatars.discourse-cdn.com/v4/letter/i/9f8e36/32.png) [@Ivan\_a](https://forum.inductiveautomation.com/u/Ivan_a)\
**Post date:** [April 24, 2018, 9:51pm UTC](https://forum.inductiveautomation.com/t/store-forward-buffer-cannot-be-emptied/17823/5 "2018-04-24T21:51:23Z")

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Thanks. We will try.

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**Author:** ![Ivan\_a](https://avatars.discourse-cdn.com/v4/letter/i/9f8e36/32.png) [@Ivan\_a](https://forum.inductiveautomation.com/u/Ivan_a)\
**Post date:** [May 4, 2018, 2:16pm UTC](https://forum.inductiveautomation.com/t/store-forward-buffer-cannot-be-emptied/17823/6 "2018-05-04T14:16:56Z")

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It looks like our problem was related to time sincronization between the redundant servers. it now works fine.