Systems: * PowerMac with dual G4 533MHz CPU's, 1GB RAM, SCSI drives * PowerMac with single G3 240MHz CPU, 264MB RAM, SCSI drives * Yellow Dog Linux-3.0.1: 2.4.25 kernel * mysql-4.1 from BK tree 29July04

============================================================= I have managed to get a two replica, four db node cluster running on two machines with drastically different resource/performance characteristics thanks to recent comments to the list from Mikael Rostrum.

The default DB configuration parameters used: [DB DEFAULT] Replicas: 2 DataMemory: 40M IndexMemory: 12M HeartbeatIntervalDbDb: 5000 <<========= TimeBetweenWatchDogCheck: 30000 <<=========

Increasing the TimeBetweenWatchdocCheck eliminated the type of db node crash on the slower machine that showed up in the log files as:

Ndb kernel is stuck in: Job Handling

Increasing the HeartbeatIntervalDbDb eliminated db node crashes arising from too many "missed heartbeats".

So... It works!

I am the first to admit that running a two replica, four node cluster on these two systems is like trying to get a dog to dance on its hind legs. To what end??? It is just a learning experiment.

For what it is worth... During the startup, the average load on the small machine climbs above 5 as the amount of memory used by swapd climbs to 300MB and the disk block I/O goes into coronary arrest. Once the cluster is stable, the average load drops to 0.6 and the block I/O settles down.

-Joseph