Disable Cache - 2015

nav_student

Hi guys,

In this article I read something disable cache.

4) Data Cache Size
This is a Microsoft Dynamics NAV Server setting, which located in CustomSettings.config file. Sets the data cache size. This is an abstract value with contextual meaning on the type of the item being cached.
<add key=”DataCacheSize” value=”9″ />
The number you specify in DataCacheSize setting determines how much memory is used for caching data.
The actual amount of memory (in MB) allocated is 2n, where n is the value of the DataCacheSize setting:
Value Memor y 9 (default) 512Mb 10 1Gb 11 2Gb 12 4Gb 13 8Gb 14 16Gb 15 32Gb …
When running a single tenant system the default value of 9 is probably good.
When running a multi-tenant system, the data cache is shared between all tenants.
Set to 0 to disable cache.
5) Metadata Provider Cache Size
This is a Microsoft Dynamics NAV Server setting, which located in CustomSettings.config file.
Sets the Metadata Provider cache size (in number in objects cached).
Set to 0 to disable cache.


Do you know what is the impact if I disable cache for a multi tenant solution?

Juhl

Never tried, but it cant be good.
The cache is very important.

RemkoD

Why would you want to disable the cache for a multi tenant solution? Is there a specific problem you want to solve? Usually you want to increase the data cache size because the cache is shared between multiple tenants.

Exceptions where disable data cache is usefull
We disable the data cache only in very specific situations. For some external applications the cache synchronization delay between multiple NST's (0 to 30 sec) is an issue.

Example: A user modifies or inserts data on NST A. The user wants to consume that data from an external application almost instantaneously. If the user and external application is connected to the same NST, this isn't a problem. In a situation where external applications are connected to other NST's this could be a problem. Because there is a delay in the cache synchronization between NSTs (up to 30 sec). In this situation we create a dedicated NST for that external application only and we disable the data cache on that NST. We never dared to disable the cache on a NST where end users or multiple applications connect to .

How to disable data cache
I thought you had to disable the DataCache with the parameter DisableDataCache in the NST configuration file.. looking at your description setting the DataCacheSize to 0 would do the same.. hmm. Anyone any thought on this?

Location:    C:\Program Files\Microsoft Dynamics NAV\100\Service\Instances\[instance naam]\CustomSettings.config
Key:         <add key="DisableDataCache" value="False" />
Key:         <add key="DataCacheSize" value="9" />

RemkoD

If you mean this part:

When running a single tenant system the default value of 9 is probably good.
When running a multi-tenant system, the data cache is shared between all tenants.
Set to 0 to disable cache.

These are three different points. I think you should read it like:

• When running a single tenant system the default value of 9 is probably good.
• When running a multi-tenant system, the data cache is shared between all tenants.
• Set to 0 to disable cache.

I don't think it's a recommendation to disable the data cache in a multi-tenant scenario More like: You can disable it if you want to. For example for a scenario i described in my previous post.

nav_student

Thanks for your answers, at the moment I'm dealing with the following error
Cache synchronization took longer than the specified - CacheSynchronizationPeriod so I'm wondering what should be the best solution.
so I was wondering and can we do to sort this issue.
The parameters applied to the CustomSettings.config appear to be the default.