in this change, the type of the "generation" field of "sstable" in the
return value of RESTful API entry point at
"/storage_service/sstable_info" is changed from "long" to "string".
this change depends on the corresponding change on tools/jmx submodule,
so we have to include the submodule change in this very commit.
this API is used by our JMX exporter, which in turn exposes the
SSTable information via the "StorageService.getSSTableInfo" mBean
operation, which returns the retrieved SSTable info as a list of
CompositeData. and "generation" is a field of an element in the
CompositeData. in general, the scylla JMX exporter is consumed
by the nodetool, which prints out returned SSTable info list with
a pretty formatted table, see
tools/java/src/java/org/apache/cassandra/tools/nodetool/SSTableInfo.java.
the nodetool's formatter is not aware of the schema or type of the
SSTables to be printed, neither does it enforce the type -- it just
tries it best to pretty print them as a tabular.
But the fields in CompositeData is typed, when the scylla JMX exporter
translates the returned SSTables from the RESTful API, it sets the
typed fields of every `SSTableInfo` when constructing `PerTableSSTableInfo`.
So, we should be consistent on the type of "generation" field on both
the JMX and the RESTful API sides. because we package the same version
of scylla-jmx and nodetool in the same precompiled tarball, and enforce
the dependencies on exactly same version when shipping deb and rpm
packages, we should be safe when it comes to interoperability of
scylla-jmx and scylla. also, as explained above, nodetool does not care
about the typing, so it is not a problem on nodetool's front.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closes#13834
b112a3b78a