tokumx and mongodb are incompatible; you couldn't build a mixed replica-set because they had different storage engines and spoke different replication languages. But PSMDB seems to have closed this gap (with pluggable storage engines, at least, which can allow wiredTiger). Does this mean they can now also be mixed (i.e. have the differences in replication-language also been rectified?) I ask because I've got a very old tokumx system with important data on it and MUST bring it into a mongodb cluster, but there seems to be no simple way to do this. If I can migrate tokumx->PSMDB->mongodb, that would be fantastic! Any help would be appreciated!
I've got a very old tokumx system with important data on it and MUST bring it into a mongodb cluster, but there seems to be no simple way to do this.
TokuMX's replication protocol is not compatible with MongoDB or Percona servers, so migrating from TokuMX will unfortunately require dumping and restoring your data. Outside of replication, there are also some incompatible TokuMX index options to remove before restoring into MongoDB.
See Migrate from TokuMX to Percona Server for migration approaches & scripts to help with this.
If I can migrate tokumx->PSMDB->mongodb, that would be fantastic!
If your goal is to migrate to MongoDB Community or Enterprise edition, an intermediate migration via PSMDB will not provide any benefit. PSMDB uses replication code from the upstream MongoDB community server, but does not provide any special migration path from TokuMX.