Mikael Ronström wrote:

Could you explain the difference between |[DB]TimeBetweenLocalCheckpoints and ||[DB]TimeBetweenGlobalCheckpoints, and how both of these relate to ||[DB]NoOfFragmentLogFiles? In the documentation on NoOfFragmentLogFiles it says, "|REDO log records aren't removed until three local checkpoints have completed since the log record was inserted. The speed of checkpoint is controlled by a set of other parameters so these parameters are all glued together ... In high update scenarios this parameter needs to be set very high. Test cases where it has been necessary to set it to over 300 have been performed." I can tell that I do not understand how these are tied together, even though I have read and reread http://dev.mysql.com/doc/mysql/en/MySQL_Cluster_DB_Definition.html.

One of the functions that I am testing is importing a large quantity of data into the cluster, and so I am trying to figure out what settings need to be what for this to be possible - I hope to be able to move a very large table (75mil rows, 8 columns: 4 int, 3 varchar(20), 1 varchar(100), all but 1 column allowed to be NULL, and charset has to be UTF8). I continue to run into problems with UNDO buffers filling up during the import process, though I have had mostly success lately, when using small import files.

A bigger problem that I am running into is that DataMemory and IndexMemory are filling up after an unexpectedly short amount of time. I have split the data into text dumpfiles of 250,000 rows (~15Mb each) and import them with mysqlimport -L. I currently have 8 DB nodes, set to 600M DataMemory and 96M IndexMemory, but I run out of DataMemory after only 3 to 4 mil rows (~200Mb of text files). In other words, 200Mb of text seem to be filling up 4.8Gb of DataMemory .... I have studied the documentation on DataMemory and IndexMemory use, but it is too confusing for me and does not seem to cover clearly the circumstances that I am working with.

Could someone please clarify these things with me? It would be most appreciated :)