Hi I have one Grails application, it uses Spring cache. I want to clone it (say APP_A and APP_B) and deploy on separate it as each access different DB and has some different configuration.
Currently I have two copy of Jetty servers (JETTY_A, JETTY_B. different port). I put APP_A in Jetty_A and APP_B in Jetty_B.
I'm not familiar with Spring cache.
Is this deployment save? I mean, will there be any mix of cache between both? Because both using the same code base. So, the cache will use the same key name.
#cacheable("someCache")
SpringCache uses EHCache under the covers. The caches are in-process caches and they do not affect caches running in other processes on the same machine, unless you had explicitly configured distributed caching.
As #KenLiu said in his answer, Spring Cache is strictly in-process when using EHCache as it's cache provider. Since you are working with Grails, however, there are better alternatives that will require only minimal changes.
The Grails Cache Plugin is a offers a Spring Cache API-compatible cache abstraction over a number of (plugable) cache providers, including some, like the Redis provider, that allow you to cache between processes (and entire machines) very easily.
Related
I have 2/3 Java/spring-boot application running in a system. I want to use common storage so that other java application can also use cache generated by any other Java/spring-boot application.
Can I create in memory ehcache with common diskstore
<!--diskStore path="D://cache//" /-->
or should I run a standalone ehcache in my machine & use it in all application
So, as far as I read, it looks like if we need to run in a server, it should be in Terracotta server & terracotta server helps in distribution
But, I rather want to centralize the cache, so other application can use common cache
So, I think I need to do without terracotta
Or is there any other cache vendor is there to support my usecase?
This is easily achieved using Hazelcast IMDG. Hazelcast IMDG can be run as seperate cluster or embedded with spring applications. To use hazelcast with Spring all you have to is to add the Spring-data-hazelcast dependency.
There are several code samples available online and it github.
Spring Data example: Click Here
Dependency project : Click here
I've got an application that uses Spring Cache (Ehcache), but now we need to add a 2nd node (same application). Can the cache be shared between the nodes or each with their own instance but synched?
Or do I need to look at a different solution?
Thanks.
That depends on your cache implementation - not on Spring, which only provides an abstract caching API. You are using EhCache as your caching implementation, which comes with a Terracotta server for basic clustering support and is open source. See http://www.ehcache.org/documentation/3.1/clustered-cache.html#clustering-concepts for more details
I'd like to know how myBatis cache (local and second level) to handle data in distributed system. I have 5 instances running against Oracle db, and I use MyBatis for data access. All 5 instances are same but running on different servers. The Mybatis are configured to use SESSION cache, which being said the cache is cleared when any insert/delete/update statement is executed.
When 1 instance runs , the local cache of that server is cleared. How does the other 4 instances know the cache needs to be flushed/renewed?
If you are using the built-in cache, no they don't. Never enable secondary cache if you are using MyBatis in a distributed environment with default cache because they don't know what happens each other and won't clear the staled cache when change happens.
You need to set up an external cache service, such as Ehcache and Redis, to make MyBatis secondary cache usable.
Please refer to http://mybatis.org/ehcache-cache/ and http://mybatis.org/redis-cache/
Giving a track:
I guess all instances are behind a load balancer and running against a single Oracle DB.
Instances nodes would better be in a cluster, otherwise, how could they communicate with each other. Then cache may be shared between cluster's nodes, for example as stated in Jboss doc, working with Hibernate.
The question is more about how to configure server (or application, in files such as beans.xml) to use MyBatis cache.
If the SessionFactory is declared #ApplicationScoped, it could be enough.
I need to cache different user and application data on a daily basis.
Context:
no experience with caches
working on a java web application that sends news articles to users displayed in a user-feed format
MySQL backend
Java middle tier using Hibernate and Jersey
I've checked out different cache technologies, and it seems like Memcached or Redis are the most used technologies in use cases similar to mine -- many reads and writes i.e. Facebook, Twitter, etc.
But I have to serialize objects before I cache them using the two above cache systems. It seemed like an unnecessary step to cache just a POJO, so I checked out POJO caches and stumbled upon JBOSS's Infinispan.
Does anyone have any good reasons why I shouldn't use Infinispan over Memcached or Redis over the serialization, and subsequent deserialization, overhead concern?
When Infinispan works in clustered mode, or when it has to offload data to external stores, it will have to face Serialization.
The good news is:
- you'll avoid any serialization costs unless it has to go somewhere else
- its own serialization mechanism is far more efficient than Java's standard serialization mechanism (and nicely customizable)
Memcached and Redis are "external" caching solutions, while with Infinispan you can keep the same Java instance cached. If this is a good or bad thing depends on your architecture specifics.
Although commonly you'll want to use a hybrid solution: use Infinispan for your in-JVM needs, cap its memory usage, have it offload what can't be fit locally to an external store, and it's easy to have it offload the extra stuff to either Redis, Memcached, another Infinispan cluster, or several other alternatives.
Your benefit is transparent integration with some popular frameworks (i.e. Hibernate) and that it can handle the serialization efficiently for you - if and when it's needed as it might need to happen in background.
I want to cluster EHCache in Play Framework 2.x web application in several node. Why everyone recommend to avoid to use EHCache as a distributed cache in Play 2.x clustered web application?
I use nginx proxy to serve request across Play node and i want to make default EHCache of each node share its content.
Well according to this EHCache page, using EHCache in distributed mode is a commercial product. So if you want to use a free distributed cache, you need something different like Memcached or Redis.
My experience deploying a (Java)Play 2.2.3 to Amazon EC2 was terrible with EHCache. It requires a few workarounds with the localhost resolve (going su for each of your nodes - hard work when you have a few dozens of servers) and regardless, being free only for standalone version without ostensively letting us know upfront is a big no-no for me. I'm done with EHCache.
Edit: moved to Redis in 2015 (thanks #Traveler)
I am not aware of any Play Framework issues here, but the use of ehcache 2.x should fine as you can set it up with JGroups (faster than RMI) and use invalidation mode (infinispan slang).
Invalidation is a clustered mode that does not actually share any data at all, but simply aims to remove data that may be stale from remote caches. This cache mode only makes sense if you have another, permanent store for your data.
In ehcache 2.x you can set up invalidation mode with replicatePuts=false in your jgroups config.
In ehcache 3.x they do not have such a mode. You have to set up a commercial Terracotta server which is a distributed cache. So all date is moved between nodes and the terracotta server.
We tried it once and failed terribly.
As ehcache2.x is no longer active we just switched to Infinispan which has all features of ehcache2.x and a lot more.
So my recommendation: Use ehcache 2.x or infinispan. Do not use ehcache 3.x