In 380f243986 we added support for rack
lists in replication options. Drivers which are not prepared to parse
that (as of now, all of them), will not create metadata object for
that keyspace. This breaks, for example, the "copy to/from" cqlsh
command. Potentially other things too.
To fix that, keep the "replication" column in the old format, and
store numeric RF there, which corresponds to the number of
replicas. Accurate options in the new format are put in
"replication_v2".
We set replication_v2 in the schema only when it differs from the old
"replication" so that the new column is not set during upgrade,
otherwise downgrade would fail. Partition tombstone is added to ensure
that pre-alter replication_v2 value is deleted on alters which change
replication to a value which is the same as the post-alter
"replication" value.
Fixes#26415Closesscylladb/scylladb#26429
Allows per-DC replication factor to be either a string, holding a
numerical value, or a list of strings, holding a list of rack names.
The rack list is not respected yet by the tablet allocator, this is
achieved in subsequent commit.
This changes the format of options stored in the flattened map
in system_schema.keyspaces#replication. Values which are rack lists,
are converted into multiple entries, with the list index appended to
the key with ':' as the separator:
For example, this extended map:
{
'dc1': '3',
'dc2': ['rack1', 'rack2']
}
is stored as a flattened map:
{
'dc1': '3',
'dc2:0': 'rack1',
'dc2:1': 'rack2'
}
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Signed-off-by: Tomasz Grabiec <tgrabiec@scylladb.com>
