Hello! Unfortunately, cache templates are not documented that good. AFAIK they were mostly implemented to be able to reference to complex cache configurations with CREATE TABLE.
As far as my understanding goes, caches from cacheConfigurations are actually started when grid starts. 1) I think that only the first one will be used to create a cache. Even if you join a node with distinct cacheConfigurations to the cluster, and it already has some caches started, those will just be re-used (by name). 2) Yes, you can have a cacheConfiguration with name "prefix*", which will lead to a) not starting this cache on grid start, and b) when you start a cache "prefix1" it will use configuration from template. There's a test for it named IgniteCacheConfigurationTemplateTest in code base. 3) Nothing will happen, it will return early if such cache already exists. 4) Yes. 5) Good question, I will have to check that. Still I won't rely on that and just always have this configuration around. 6) See above about the '*'. Regards, -- Ilya Kasnacheev сб, 25 авг. 2018 г. в 0:55, Dave Harvey <dhar...@jobcase.com>: > I found what I've read in this area confusing, and here is my current > understanding. > > When creating an IgniteConfiguration in Java or XML, I can specify the > property cacheConfiguration, which is an array of CacheConfigurations. > This causes Ignite to preserve these configurations, but this will not > cause Ignite to create a cache. If I call > Ignite.getOrCreateCache(string), if there is an existing cache, I will get > that, otherwise a new cache will be created using that configuration. > > It seems like creating a cache with a configuration will add to this list, > because Ignite.configuration.getCacheConfiguration() returns all caches. > > > I can later call Ignite.addCacheConfiguration(). This will add a template > to that list. > > Questions: > 1) what happens if there are entries with duplicate names on > IgniteConfiguration.setCacheConfiguration() when this is used to create a > grid? > 2) There was mention in one e-mail talking about a convention where > templates have "*" in their name? > 3) What happens if addCacheConfiguration() tries to add a duplicate name? > 4) Is a template simply a cache that not fully instantiated? > 5) What about template persistence? Are they persisted if they specify a > region that is persistent? > 6) My use case is that I want to create caches based some default for the > cluster, so in Java I would like to construct the new configuration from > the a template of a known name. So far, I can only see that I can call > Ignite.configuration.getCacheConfiguration() and then search the array for > a matching name. Is there a better way? > > > *Disclaimer* > > The information contained in this communication from the sender is > confidential. It is intended solely for use by the recipient and others > authorized to receive it. If you are not the recipient, you are hereby > notified that any disclosure, copying, distribution or taking action in > relation of the contents of this information is strictly prohibited and may > be unlawful. > > This email has been scanned for viruses and malware, and may have been > automatically archived by *Mimecast Ltd*, an innovator in Software as a > Service (SaaS) for business. Providing a *safer* and *more useful* place > for your human generated data. Specializing in; Security, archiving and > compliance. To find out more Click Here > <http://www.mimecast.com/products/>. >
