[jira] [Commented] (GEODE-8235) Server should not be required to have an available PDX type registry for ClientCache applications

["John Blum (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/GEODE-8235?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17129890#comment-17129890 ] 

John Blum commented on GEODE-8235:
----------------------------------

The reason why the {{Exception}}, and specifically the {{CacheClosedException}} is "inappropriate" (essentially unhelpful and useless) in this case is because, I could possibly handle this situation in my application by converting the JSON to an Object or some other form, but a {{CacheClosedException}} could be thrown by Geode for countless reasons, which leaves a developer to have to parse the clumsy {{Exception}} message, which is naive and error prone.


A more appropriate {{PdxTypeRegistryNotAvailableException}} (a {{RuntimeException}}) would have been more appropriate, even if wrapped in a {{CacheClosedException}} because perhaps the {{ClientCache}} is closing.

However, I would argue that a {{region.put(key, pdxBytes);}} should not cause a {{ClientCache}} application failure and subsequently close the cache unnecessarily from underneath the app, especially since this condition IS recoverable.


> Server should not be required to have an available PDX type registry for ClientCache applications
> -------------------------------------------------------------------------------------------------
>
>                 Key: GEODE-8235
>                 URL: https://issues.apache.org/jira/browse/GEODE-8235
>             Project: Geode
>          Issue Type: Bug
>          Components: serialization
>            Reporter: John Blum
>            Priority: Major
>              Labels: JSON-PDX
>
> As an application developer using Apache Geode, if I create a {{ClientCache}} application that contains client {{LOCAL}} 
> Regions only (i.e. with {{ClientRegionShortcut.LOCAL}}) and I attempt to store objects in PDX serialized format, then Geode will throw an inappropriate {{Exception}}:
> ACTUAL:
> {code}
> Caused by: org.apache.geode.pdx.JSONFormatterException: Could not parse JSON document: [Source: (String)"{"@type":"example.app.model.Customer","id":1,"name":"Jon Doe"}"; line: 1, column: 63]
> 	at org.apache.geode.pdx.JSONFormatter.toPdxInstance(JSONFormatter.java:206) ~[geode-core-1.12.0.jar:na]
> 	at org.apache.geode.pdx.JSONFormatter.fromJSON(JSONFormatter.java:134) ~[geode-core-1.12.0.jar:na]
> 	at ...
> 	... 39 common frames omitted
> Caused by: org.apache.geode.cache.CacheClosedException: Client pools have been closed so the PDX type registry is not available.
> 	at org.apache.geode.internal.cache.GemFireCacheImpl.getCacheClosedException(GemFireCacheImpl.java:1630) ~[geode-core-1.12.0.jar:na]
> 	at org.apache.geode.internal.cache.GemFireCacheImpl.getCacheClosedException(GemFireCacheImpl.java:1619) ~[geode-core-1.12.0.jar:na]
> 	at org.apache.geode.pdx.internal.ClientTypeRegistration.getAllPools(ClientTypeRegistration.java:153) ~[geode-core-1.12.0.jar:na]
> 	at org.apache.geode.pdx.internal.ClientTypeRegistration.defineType(ClientTypeRegistration.java:63) ~[geode-core-1.12.0.jar:na]
> 	at org.apache.geode.pdx.internal.TypeRegistry.defineType(TypeRegistry.java:202) ~[geode-core-1.12.0.jar:na]
> 	at org.apache.geode.pdx.internal.TypeRegistry.defineLocalType(TypeRegistry.java:250) ~[geode-core-1.12.0.jar:na]
> 	at org.apache.geode.pdx.internal.PdxWriterImpl.completeByteStreamGeneration(PdxWriterImpl.java:540) ~[geode-core-1.12.0.jar:na]
> 	at org.apache.geode.pdx.internal.PdxInstanceFactoryImpl.create(PdxInstanceFactoryImpl.java:64) ~[geode-core-1.12.0.jar:na]
> 	at org.apache.geode.pdx.internal.json.PdxInstanceHelper.endObjectField(PdxInstanceHelper.java:209) ~[geode-core-1.12.0.jar:na]
> 	at org.apache.geode.pdx.JSONFormatter.getPdxInstance(JSONFormatter.java:309) ~[geode-core-1.12.0.jar:na]
> 	at org.apache.geode.pdx.JSONFormatter.toPdxInstance(JSONFormatter.java:199) ~[geode-core-1.12.0.jar:na]
> 	... 55 common frames omitted
> {code}
> First of all this is not even an appropriate Exception!  {{CacheCloseException}} because my client had no open Pools to an available server with a PDX type registry.
> 1. Creating client local-only applications not connected to an entire cluster or server is a very useful and practical arrangement during development.
> 2. My application should not have to be a peer {{Cache}} to have an available PDX type registry to store PDX instances in client {{LOCAL}} Regions.
> 3. It is actually highly useful to run my application in local-only mode, in a local-only context (i.e. with only client {{LOCAL}} Regions) without a cluster or server for development, testing and debugging purposes.
> 4. It is also really useful if my application can also store PDX bytes, even in client {{LOCAL}} (only) Regions for development, testing and debugging purposes.
> Some find it hard to imagine why an application would want to do this, store PDX instead of POJOs.  However, consider the fact that my application might be part of a larger Microservices architecture that communicate via a RESTful interfaces.  They pass JSON back and forth, which might either be complex or unstructured.  Either way, it is possible I don't have or don't want to create POJOs (types) matching the JSON that my Microservice consumes.  I simply want access to certain bits of information which PDX is adequately suited for.  These client LOCAL Regions might even be temporary.  When connected, I might even want to share this data (or aggregated data) with Native Clients which most certainly won't have Java types matching the JSON content, raw or summarized.
> EXPECTED:
> As a developer using Apache Geode, I expected to be able to develop (primarily) {{ClientCache}} applications, run them locally with client {{LOCAL}} Regions, storing data in PDX format as necessary, all without requiring a complex setup (e.g. such as a cluster or a server).



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