Using spring data neo4j in liferay portlets, Neo4j is locking itself when a portlet is using it, encounter exception like below
Unable to lock store [db.name], this is usually a result of some other Neo4j kernel running using the same store
Is there any way to run multiple portlets with same embedded neo4j db. Can i use Neo4j HA? Looks like Neo4j HA to going to deal with multi-servers, but i only one server. Any ideas?
Thanks in advance!
Did you try including neo4j library files at portal level instead of using at portlet level ?
i.e. to place required .jar files in /lib/ext instead of inside WEB-INF of every portlet.
I'm not an expert in neo4j, but having good experience with liferay. Suggesting above solution from liferay point to ensure common place for all portlets.
Related
I want to know if there's a way to configure the datasource for Ignite as Elastic Search. I was browsing the web. But I did not find a solution.
I want to implement this integration for a Java application.
If I understand your idea correctly there's a way to do it. As far as I can see Elasticsearch supports SQL table-like data access and it's available through jdbc connection. From the Ignite's side we have 3rd party persistance, it uses jdbc to connect to an underlying store system. To be honest I haven't tested it but I suppose it should work.
Also I need mention that you can use GridGain WebConsole to generate simple Ignite project from existing jdbc connection. This functionality could be found on Configuration tab -> Create Cluster Configuration.
In my previous spring projects, I always use hibernate+postgresql to store the data. I rencently start to use spring-boot, and I am looking for a database system which allow me embed it in my project, without be required the installation of a external DBMS.
I try use SQLite, but in my searches I found some afirmations Hibernate isn't compatible with SQLite.
Anyone knows if this is possible and could point me a solution?
We've successfuly used HSQLDB with Hibernate for ages.
This is actually super cool for sales, you can demonstrate a working application on (potential) customers machine with the embedded HSQLDB database. And still be able to switch to "the real thing" later on.
See also this:
Does Hibernate Fully Support SQLite
and this:
https://code.google.com/p/hibernate-sqlite/
I was advised to develop Neo4j extension because of poor performance due to the many calls to the Neo4j REST interface introduced by Spring Data Neo4j. For the good start I was able to run simply Neo4j extension from Neo4j documentation:
http://docs.neo4j.org/chunked/stable/server-unmanaged-extensions.html
Now I have to move some logic from my web service to Neo4j extension to make communication between them as small as possible. However, my web service is based on Spring Data Neo4j as well as Spring Data JPA, so to reuse my actual code I would like to use also Spring Data in my extension. I have found this documentation:
http://docs.spring.io/spring-data/data-neo4j/docs/current/reference/html/reference_neo4j-server.html
but it is not clear for me and there is no working example. Is there any sample code with such integration?
There is a great example on using SDN in an unmanage extension, see http://inserpio.wordpress.com/2014/04/30/extending-the-neo4j-server-with-spring-data-neo4j/.
To reduce database hits, I've used static variables to store data from database.
At time of WAR deployment this data is stored in these variabes as it is not changing so frequently.
This scenario was working fine as the scope was with only single a WAR. Now I have another application where I need access to these varibles
But due to different application scope,I'm unable to access them in another application.
Also I'm having an EAR which encloses both above WAR and one JAR containing some common buisness logic of both WARs.
So under EAR is it possible to share these variables via JAR or using some different approach?
If any javaEE concept can help in this scenario, then please let me know about it also.
I'm using maven with Jboss7.1.1.Final for this
You should use Infinispan, the built-in caching mechanism of JBoss 7 https://docs.jboss.org/author/display/ISPN/Getting+Started+Guide+-+JBoss+AS+7. Caching data in static fields is generally frowned upon in Java EE.
However should you still want to cache your data in static fields you need to make sure the class with the cache was to be shared across all WARs. This means you have to create skinny WARs.
Looks like you need an Enterprise Caching Solutions. There are lots of choices on the market. They include but not limit to
Open Source framework
Memcached
EHCache
Infinispan (mentioned by Phillipe)
Commercial product
Oracle Coherence
GigaSpaces XAP
GemFire
For your second question, as long as your JAR is deployed in the EAR/lib folder, you should be fine.
I am trying to integrate a simple Enterprise App to a data source(xml file for now) using Apache Service Mix(ASM) ESB. Basically I need to have the ESB pick up content from the xml file and populate corresponding tables in a H2 database(which my app is linked to). I am not sure as to which features of ASM I should be using for the same. If someone could give me a high level idea as to how I should be going about the same I would be very grateful. I have looked at documentation from Fuse ESB and also the ASM documentation but at this point I am totally confused.
Thanks in advance.
Since ServiceMix uses Camel for such work, my first suggestion is to take a look at Apache Camel for it.
For you're example a simple route would look like this:
from("file:location_of_file").unmarshal(registered-jaxB-structure)
.split(simple("probably_your_entities")).to("jdbc:dataSource?sql_insert");
You read your incoming file from the *location_of_file* unmarshall it since it's a XML file to your object-structure with jaxb. After that you probably need to iterate over the entities inside your xml file which is best be done with a split. Now your structure is most likely in a way you can use either for storing with jpa, sql or jdbc.