Teiid Designer is a modelling environment for the creation of virtual databases (VDBs) that fuse together different types of information store. The produced VDB files are uploaded to a Teiid instance installed on a running Jboss server.
Interaction with Teiid
In order to create a VDB, Teiid Designer requires interaction with a Teiid instance in the following ways:
- Access and display the installed Teiid translators;
- Access, display and (if necessary) remove existing datasources and VDBs;
- Upload local VDBs as either completed artifacts or interim previews;
- Execute uploaded VDBs by connecting to them using the Teiid JDBC Driver and query their fused data.
History of the Architecture
- The Teiid server used to be an independent entity running under its own port on a computer. As of Teiid version 7, the project sought to integrate the server into Jboss as a set of modules and subsystems. However, the external Teiid client API remained the same.
- The Teiid project provides a separate runtime client for accessing a Teiid instance. This client is totally independent of Eclipse and Jboss Tools (JBT) and serves as a library that users can integrate into their own projects.
- Older versions of Teiid Designer used to integrate Teiid's runtime client library as a binary jar into its codebase. However, this had the limitation that only the Teiid client and the same version of the Teiid instance could be guaranteed compatibility.
- As of version 8.0 of Teiid Designer, the Teiid client began to be forked, with 3 versions of the client being present in version 8.4. This process has proven unsustainable in the long-term and the client has been paired back to a single version that is modified to be backward and forward compatible with each new version of Teiid.
Current Status of the Teiid Client
Due to the historical evolution of the Designer Teiid runtime client and the requirement to follow Teiid's upstream version, the client's dependencies are a hybrid of nested libraries (auto-downloaded via maven) and Eclipse dependencies.
Teiid Client Eclipse Dependencies:
Teiid Client Nested Runtime Libraries:
Increasingly, it is becoming clear that this approach is also unsustainable since the nested integration of Teiid Designer with JBT implies the possible existence at runtime of 2 versions of the same library, eg. jboss-dmr. This can present problems and may even be the cause of lockup issues and other odd behaviour.
For Teiid Designer to properly integrate with JBT, it needs to re-engineer the Teiid client internals to make use of the JBT libraries and framework rather than interfacing at the lower level of communicating directly with the Jboss server. For example, in order to get the client to compile without the nested Jboss libraries, the following classes will need to be modified:
Consideration of Limitations of such Future Development
- Designer's Teiid runtime client remains largely independent of JBT dependencies. The Komodo branch of Designer has successfully implemented a Teiid client that has no Eclipse or JBT dependencies at all. For the internals of the client to rely on JBT, this would no longer be possible and would necessarily tie the clients future with JBT and eclipse.
Questions for Discussion
- How would the Teiid client classes be modified to interface with the JBT API rather than directly with jboss.as?
- Should the Teiid client be modified in Teiid Designer to more directly depend on JBT and lose some of its independence?
- Could the existing client architecture be preserved to allow for an intelligent client that knows what environment it is running in and use the most appropriate connection mechanism or more simply be broken into 2 clients, a JBT version and a standalone version?
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