Oracle 5.0 Reference Manual page 1586

BatchSizePerLocalScan
nodes.
•
LongMessageBuffer
Effective Version
MySQL 5.0.0
Restart Type: N
This is an internal buffer used for passing messages within individual nodes and between nodes.
Although it is highly unlikely that this would need to be changed, it is configurable. By default, it is set
to 1MB.
Logging and checkpointing.
behavior.
•
NoOfFragmentLogFiles
Effective Version
MySQL 5.0.0
Restart Type: IN
This parameter sets the number of REDO log files for the node, and thus the amount of space
allocated to REDO logging. Because the REDO log files are organized in a ring, it is extremely
important that the first and last log files in the set (sometimes referred to as the "head" and "tail" log
files, respectively) do not meet. When these approach one another too closely, the node begins
aborting all transactions encompassing updates due to a lack of room for new log records.
A log record is not removed until three local checkpoints have been completed since that
REDO
log record was inserted. Checkpointing frequency is determined by its own set of configuration
parameters discussed elsewhere in this chapter.
How these parameters interact and proposals for how to configure them are discussed in
Section 17.3.2.11, "Configuring MySQL Cluster Parameters for Local
The default parameter value is 8, which means 8 sets of 4 16MB files for a total of 512MB. In other
words, REDO log space is always allocated in blocks of 64MB. In scenarios requiring a great many
updates, the value for
to provide sufficient space for REDO logs.
If the checkpointing is slow and there are so many writes to the database that the log files are full
and the log tail cannot be cut without jeopardizing recovery, all updating transactions are aborted
with internal error code 410
until a checkpoint has completed and the log tail can be moved forward.
Important
This parameter cannot be changed "on the fly"; you must restart the node
using --initial. If you wish to change this value for all data nodes in a
running cluster, you can do so using a rolling node restart (using
when starting each data node).
•
MaxNoOfOpenFiles
MySQL Cluster Configuration Files
has a strong connection to the
Type/Units
bytes
The following
Type/Units
integer
NoOfFragmentLogFiles
(Out of log file space
1566
BatchSize
Default
1M
parameters control log and checkpoint
[ndbd]
Default
8
may need to be set as high as 300 or even higher
temporarily). This condition prevails
[1584] defined in the SQL
Range/Values
512K - 4G
Range/Values
3 - 4G
Checkpoints".
--initial