OpenCensus 0.28.0 broke Java 7 compatibility

[elharo]

We're not ready to remove Java 7 support yet. We should revert this to 0.24.0.

see googleapis/java-shared-dependencies#248 (comment)

[ericgribkoff]

cc @ejona86

[ejona86]

@elharo, how is it not Java 7 compatible? The comment you link to just links to grpc-auth and doesn't provide any explanation. I poked at the CI results and don't see anything useful there. There's no mention in open census release notes. A small sampling of class files in opencensus-api and opencensus-impl show Java 7 bytecode, which agrees with the code. I don't see a commit since 0.24.0 that would obviously break compatibility.

[elharo]

@stephaniewang526 can you elaborate? I might have misread your comment, which is about OpenCensus 0.28.0. And it looks like the CI is passing? A lot fo the CIs have been messy lately.

[elharo]

@ejona86 I might have misspoke. It appears that the problem is that gRPC updated to OpenCensus 0.28.0 while we're trying to stick to 0.24.0 everywhere else in the stack. That might be what we want to revert.

[stephaniewang526]

@stephaniewang526 can you elaborate? I might have misread your comment, which is about OpenCensus 0.28.0. And it looks like the CI is passing? A lot fo the CIs have been messy lately.

This update in particular would not work in any of the Java clients downstream at the moment due to dependency conflicts with gax-java v1.60.1 and that we decided last year to pin OpenCensus version at 0.24.0 since it was not going 1.0 (not Java 7 compat issue actually -- the Java 7 compat comment was meant for a different dependency):

+-com.google.cloud:google-cloud-bigqueryconnection:1.0.9-SNAPSHOT
  +-com.google.api:gax:1.60.1
    +-io.opencensus:opencensus-api:0.24.0
and
+-com.google.cloud:google-cloud-bigqueryconnection:1.0.9-SNAPSHOT
  +-com.google.api:gax-grpc:1.60.1
    +-io.grpc:grpc-auth:1.35.0 (managed) <-- io.grpc:grpc-auth:1.32.2
      +-io.opencensus:opencensus-api:0.24.0 (managed) <-- io.opencensus:opencensus-api:0.28.0
and
+-com.google.cloud:google-cloud-bigqueryconnection:1.0.9-SNAPSHOT
  +-com.google.api:gax:1.60.1
    +-com.google.auth:google-auth-library-oauth2-http:0.22.2 (managed) <-- com.google.auth:google-auth-library-oauth2-http:0.22.0
      +-com.google.http-client:google-http-client:1.38.1 (managed) <-- com.google.http-client:google-http-client:1.38.0
        +-io.opencensus:opencensus-api:0.24.0
and
+-com.google.cloud:google-cloud-bigqueryconnection:1.0.9-SNAPSHOT
  +-com.google.api:gax:1.60.1
    +-com.google.auth:google-auth-library-oauth2-http:0.22.2 (managed) <-- com.google.auth:google-auth-library-oauth2-http:0.22.0
      +-com.google.http-client:google-http-client:1.38.1 (managed) <-- com.google.http-client:google-http-client:1.38.0
        +-io.opencensus:opencensus-contrib-http-util:0.24.0
          +-io.opencensus:opencensus-api:0.24.0
]

I made this change and am waiting for Jeff's review.

I believe we can close this ticket. Sorry about the confusion.

[elharo]

I'd still like to revert gRPC to OpenCensus 0.24, even if we don't need to do it for Java 7 compatibility reasons. Otherwise this change is eventually going to ripple through all the clients and force every project to upgrade. I wish we'd never added this on at all, but that ship has sailed.

[ejona86]

We'll be trying to get on OpenCensus 0.28.3 as it tries to ease migration to OpenTelemetry. And upgrading is still useful, as it ensures we are actually compatible with the newer version; that's the only reason we realized that 0.28.2 was broken got a 0.28.3 release with fixes (which I hadn't realized had actually been released). I think we could upgrade to 0.28.3 now, in time for our next release in February. We'll be wanting to change to some new APIs introduced in 0.28.3, but that can happen later.

It seems perverted to use "all projects have to use the same version" to say "you can't upgrade a dependency, even though there are no compatibility issues with the upgrade."

[ejona86]

@elharo, how many projects are actually depending on opencensus/grpc-census. Since we removed the census dependency from grpc-core, it would seem not many projects should be impacted. And those that are will want to eventually upgrade to 0.28.3.

[elharo]

OpenCensus is an unusual one. The OpenCensus team told us several versions ago, maybe circa 0.23 or 0.24, that there would be no more releases of OpenCensus and we should move to OpenTelemetry. We thus decided to stick to OpenCensus until OpenTelemetry was ready. Predicting the future is hard. :-)

I think @stephaniewang526 's dependency tree above shows how gRPC contributes dependencies on opencensus downstream.

[ejona86]

If you look at the recent releases, they have all been very small. The most recent patch releases in 0.28.x have actually included feature releases for OpenTelemetry migration.

I think @stephaniewang526 's dependency tree above shows how gRPC contributes dependencies on opencensus downstream.

It doesn't to me. I'd expect few downstreams to explicitly redefine the opencensus version. I agree that there are many users of grpc, but that's not at all what I was talking about.

[ejona86]

Seems like this is resolved. If not, comment, and it can be reopened.