MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0
The listings in this section provide information about
parameters used in the [ndbd] or
[ndbd default] sections of a
config.ini file for configuring NDB Cluster
data nodes. For detailed descriptions and other additional
information about each of these parameters, see
Section 25.4.3.6, “Defining NDB Cluster Data Nodes”.
These parameters also apply to ndbmtd, the multithreaded version of ndbd. A separate listing of parameters specific to ndbmtd follows.
Arbitration:
How arbitration should be performed to avoid split-brain
issues in event of node failure.
ArbitrationTimeout:
Maximum time (milliseconds) database partition waits for
arbitration signal.
BackupDataBufferSize:
Default size of databuffer for backup (in bytes).
BackupDataDir:
Path to where to store backups. Note that string '/BACKUP'
is always appended to this setting, so that *effective*
default is FileSystemPath/BACKUP.
BackupDiskWriteSpeedPct:
Sets percentage of data node's allocated maximum write speed
(MaxDiskWriteSpeed) to reserve for LCPs when starting
backup.
BackupLogBufferSize:
Default size of log buffer for backup (in bytes).
BackupMaxWriteSize:
Maximum size of file system writes made by backup (in
bytes).
BackupMemory:
Total memory allocated for backups per node (in bytes).
BackupReportFrequency:
Frequency of backup status reports during backup in seconds.
BackupWriteSize:
Default size of file system writes made by backup (in
bytes).
BatchSizePerLocalScan:
Used to calculate number of lock records for scan with hold
lock.
BuildIndexThreads:
Number of threads to use for building ordered indexes during
system or node restart. Also applies when running
ndb_restore --rebuild-indexes. Setting this parameter to 0
disables multithreaded building of ordered indexes.
CompressedBackup:
Use zlib to compress backups as they are written.
CompressedLCP:
Write compressed LCPs using zlib.
ConnectCheckIntervalDelay:
Time between data node connectivity check stages. Data node
is considered suspect after 1 interval and dead after 2
intervals with no response.
CrashOnCorruptedTuple:
When enabled, forces node to shut down whenever it detects
corrupted tuple.
DataDir:
Data directory for this node.
DataMemory:
Number of bytes on each data node allocated for storing
data; subject to available system RAM and size of
IndexMemory.
DefaultHashMapSize:
Set size (in buckets) to use for table hash maps. Three
values are supported: 0, 240, and 3840.
DictTrace:
Enable DBDICT debugging; for NDB development.
DiskDataUsingSameDisk:
Set to false if Disk Data tablespaces are located on
separate physical disks.
DiskIOThreadPool:
Number of unbound threads for file access, applies to disk
data only.
Diskless:
Run without using disk.
DiskPageBufferEntries:
Memory to allocate in DiskPageBufferMemory; very large disk
transactions may require increasing this value.
DiskPageBufferMemory:
Number of bytes on each data node allocated for disk page
buffer cache.
DiskSyncSize:
Amount of data written to file before synch is forced.
EnablePartialLcp:
Enable partial LCP (true); if this is disabled (false), all
LCPs write full checkpoints.
EnableRedoControl:
Enable adaptive checkpointing speed for controlling redo log
usage.
EncryptedFileSystem:
Encrypt local checkpoint and tablespace files. EXPERIMENTAL;
NOT SUPPORTED IN PRODUCTION.
EventLogBufferSize:
Size of circular buffer for NDB log events within data
nodes.
ExecuteOnComputer:
String referencing earlier defined COMPUTER.
ExtraSendBufferMemory:
Memory to use for send buffers in addition to any allocated
by TotalSendBufferMemory or SendBufferMemory. Default (0)
allows up to 16MB.
FileSystemPath:
Path to directory where data node stores its data (directory
must exist).
FileSystemPathDataFiles:
Path to directory where data node stores its Disk Data
files. Default value is FilesystemPathDD, if set; otherwise,
FilesystemPath is used if it is set; otherwise, value of
DataDir is used.
FileSystemPathDD:
Path to directory where data node stores its Disk Data and
undo files. Default value is FileSystemPath, if set;
otherwise, value of DataDir is used.
FileSystemPathUndoFiles:
Path to directory where data node stores its undo files for
Disk Data. Default value is FilesystemPathDD, if set;
otherwise, FilesystemPath is used if it is set; otherwise,
value of DataDir is used.
FragmentLogFileSize:
Size of each redo log file.
HeartbeatIntervalDbApi:
Time between API node-data node heartbeats. (API connection
closed after 3 missed heartbeats).
HeartbeatIntervalDbDb:
Time between data node-to-data node heartbeats; data node
considered dead after 3 missed heartbeats.
HeartbeatOrder:
Sets order in which data nodes check each others' heartbeats
for determining whether given node is still active and
connected to cluster. Must be zero for all data nodes or
distinct nonzero values for all data nodes; see
documentation for further guidance.
HostName:
Host name or IP address for this data node.
IndexMemory:
Number of bytes on each data node allocated for storing
indexes; subject to available system RAM and size of
DataMemory.
IndexStatAutoCreate:
Enable/disable automatic statistics collection when indexes
are created.
IndexStatAutoUpdate:
Monitor indexes for changes and trigger automatic statistics
updates.
IndexStatSaveScale:
Scaling factor used in determining size of stored index
statistics.
IndexStatSaveSize:
Maximum size in bytes for saved statistics per index.
IndexStatTriggerPct:
Threshold percent change in DML operations for index
statistics updates. Value is scaled down by
IndexStatTriggerScale.
IndexStatTriggerScale:
Scale down IndexStatTriggerPct by this amount, multiplied by
base 2 logarithm of index size, for large index. Set to 0 to
disable scaling.
IndexStatUpdateDelay:
Minimum delay between automatic index statistics updates for
given index. 0 means no delay.
InitFragmentLogFiles:
Initialize fragment log files, using sparse or full format.
InitialLogFileGroup:
Describes log file group that is created during initial
start. See documentation for format.
InitialNoOfOpenFiles:
Initial number of files open per data node. (One thread is
created per file).
InitialTablespace:
Describes tablespace that is created during initial start.
See documentation for format.
InsertRecoveryWork:
Percentage of RecoveryWork used for inserted rows; has no
effect unless partial local checkpoints are in use.
KeepAliveSendInterval:
Time between keep-alive signals on links between data nodes,
in milliseconds. Set to 0 to disable.
LateAlloc:
Allocate memory after connection to management server has
been established.
LcpScanProgressTimeout:
Maximum time that local checkpoint fragment scan can be
stalled before node is shut down to ensure systemwide LCP
progress. Use 0 to disable.
LocationDomainId:
Assign this data node to specific availability domain or
zone. 0 (default) leaves this unset.
LockExecuteThreadToCPU:
Comma-delimited list of CPU IDs.
LockMaintThreadsToCPU:
CPU ID indicating which CPU runs maintenance threads.
LockPagesInMainMemory:
0=disable locking, 1=lock after memory allocation, 2=lock
before memory allocation.
LogLevelCheckpoint:
Log level of local and global checkpoint information printed
to stdout.
LogLevelCongestion:
Level of congestion information printed to stdout.
LogLevelConnection:
Level of node connect/disconnect information printed to
stdout.
LogLevelError:
Transporter, heartbeat errors printed to stdout.
LogLevelInfo:
Heartbeat and log information printed to stdout.
LogLevelNodeRestart:
Level of node restart and node failure information printed
to stdout.
LogLevelShutdown:
Level of node shutdown information printed to stdout.
LogLevelStartup:
Level of node startup information printed to stdout.
LogLevelStatistic:
Level of transaction, operation, and transporter information
printed to stdout.
LongMessageBuffer:
Number of bytes allocated on each data node for internal
long messages.
MaxAllocate:
No longer used; has no effect.
MaxBufferedEpochs:
Allowed numbered of epochs that subscribing node can lag
behind (unprocessed epochs). Exceeding causes lagging
subscribers to be disconnected.
MaxBufferedEpochBytes:
Total number of bytes allocated for buffering epochs.
MaxDiskDataLatency:
Maximum allowed mean latency of disk access (ms) before
starting to abort transactions.
MaxDiskWriteSpeed:
Maximum number of bytes per second that can be written by
LCP and backup when no restarts are ongoing.
MaxDiskWriteSpeedOtherNodeRestart:
Maximum number of bytes per second that can be written by
LCP and backup when another node is restarting.
MaxDiskWriteSpeedOwnRestart:
Maximum number of bytes per second that can be written by
LCP and backup when this node is restarting.
MaxFKBuildBatchSize:
Maximum scan batch size to use for building foreign keys.
Increasing this value may speed up builds of foreign keys
but impacts ongoing traffic as well.
MaxDMLOperationsPerTransaction:
Limit size of transaction; aborts transaction if it requires
more than this many DML operations.
MaxLCPStartDelay:
Time in seconds that LCP polls for checkpoint mutex (to
allow other data nodes to complete metadata
synchronization), before putting itself in lock queue for
parallel recovery of table data.
MaxNoOfAttributes:
Suggests total number of attributes stored in database (sum
over all tables).
MaxNoOfConcurrentIndexOperations:
Total number of index operations that can execute
simultaneously on one data node.
MaxNoOfConcurrentOperations:
Maximum number of operation records in transaction
coordinator.
MaxNoOfConcurrentScans:
Maximum number of scans executing concurrently on data node.
MaxNoOfConcurrentSubOperations:
Maximum number of concurrent subscriber operations.
MaxNoOfConcurrentTransactions:
Maximum number of transactions executing concurrently on
this data node, total number of transactions that can be
executed concurrently is this value times number of data
nodes in cluster.
MaxNoOfFiredTriggers:
Total number of triggers that can fire simultaneously on one
data node.
MaxNoOfLocalOperations:
Maximum number of operation records defined on this data
node.
MaxNoOfLocalScans:
Maximum number of fragment scans in parallel on this data
node.
MaxNoOfOpenFiles:
Maximum number of files open per data node.(One thread is
created per file).
MaxNoOfOrderedIndexes:
Total number of ordered indexes that can be defined in
system.
MaxNoOfSavedMessages:
Maximum number of error messages to write in error log and
maximum number of trace files to retain.
MaxNoOfSubscribers:
Maximum number of subscribers.
MaxNoOfSubscriptions:
Maximum number of subscriptions (default 0 = MaxNoOfTables).
MaxNoOfTables:
Suggests total number of NDB tables stored in database.
MaxNoOfTriggers:
Total number of triggers that can be defined in system.
MaxNoOfUniqueHashIndexes:
Total number of unique hash indexes that can be defined in
system.
MaxParallelCopyInstances:
Number of parallel copies during node restarts. Default is
0, which uses number of LDMs on both nodes, to maximum of
16.
MaxParallelScansPerFragment:
Maximum number of parallel scans per fragment. Once this
limit is reached, scans are serialized.
MaxReorgBuildBatchSize:
Maximum scan batch size to use for reorganization of table
partitions. Increasing this value may speed up table
partition reorganization but impacts ongoing traffic as
well.
MaxStartFailRetries:
Maximum retries when data node fails on startup, requires
StopOnError = 0. Setting to 0 causes start attempts to
continue indefinitely.
MaxUIBuildBatchSize:
Maximum scan batch size to use for building unique keys.
Increasing this value may speed up builds of unique keys but
impacts ongoing traffic as well.
MemReportFrequency:
Frequency of memory reports in seconds; 0 = report only when
exceeding percentage limits.
MinDiskWriteSpeed:
Minimum number of bytes per second that can be written by
LCP and backup.
MinFreePct:
Percentage of memory resources to keep in reserve for
restarts.
NodeGroup:
Node group to which data node belongs; used only during
initial start of cluster.
NodeGroupTransporters:
Number of transporters to use between nodes in same node
group.
NodeId:
Number uniquely identifying data node among all nodes in
cluster.
NoOfFragmentLogFiles:
Number of 16 MB redo log files in each of 4 file sets
belonging to data node.
NoOfReplicas:
Number of copies of all data in database.
Numa:
(Linux only; requires libnuma) Controls NUMA support.
Setting to 0 permits system to determine use of interleaving
by data node process; 1 means that it is determined by data
node.
ODirect:
Use O_DIRECT file reads and writes when possible.
ODirectSyncFlag:
O_DIRECT writes are treated as synchronized writes; ignored
when ODirect is not enabled, InitFragmentLogFiles is set to
SPARSE, or both.
RealtimeScheduler:
When true, data node threads are scheduled as real-time
threads. Default is false.
RecoveryWork:
Percentage of storage overhead for LCP files: greater value
means less work in normal operations, more work during
recovery.
RedoBuffer:
Number of bytes on each data node allocated for writing redo
logs.
RedoOverCommitCounter:
When RedoOverCommitLimit has been exceeded this many times,
transactions are aborted, and operations are handled as
specified by DefaultOperationRedoProblemAction.
RedoOverCommitLimit:
Each time that flushing current redo buffer takes longer
than this many seconds, number of times that this has
happened is compared to RedoOverCommitCounter.
RequireEncryptedBackup:
Whether backups must be encrypted (1 = encryption required,
otherwise 0).
ReservedConcurrentIndexOperations:
Number of simultaneous index operations having dedicated
resources on one data node.
ReservedConcurrentOperations:
Number of simultaneous operations having dedicated resources
in transaction coordinators on one data node.
ReservedConcurrentScans:
Number of simultaneous scans having dedicated resources on
one data node.
ReservedConcurrentTransactions:
Number of simultaneous transactions having dedicated
resources on one data node.
ReservedFiredTriggers:
Number of triggers having dedicated resources on one data
node.
ReservedLocalScans:
Number of simultaneous fragment scans having dedicated
resources on one data node.
ReservedTransactionBufferMemory:
Dynamic buffer space (in bytes) for key and attribute data
allocated to each data node.
RestartOnErrorInsert:
Control type of restart caused by inserting error (when
StopOnError is enabled).
RestartSubscriberConnectTimeout:
Amount of time for data node to wait for subscribing API
nodes to connect. Set to 0 to disable timeout, which is
always resolved to nearest full second.
SchedulerExecutionTimer:
Number of microseconds to execute in scheduler before
sending.
SchedulerResponsiveness:
Set NDB scheduler response optimization 0-10; higher values
provide better response time but lower throughput.
SchedulerSpinTimer:
Number of microseconds to execute in scheduler before
sleeping.
ServerPort:
Port used to set up transporter for incoming connections
from API nodes.
SharedGlobalMemory:
Total number of bytes on each data node allocated for any
use.
SpinMethod:
Determines spin method used by data node; see documentation
for details.
StartFailRetryDelay:
Delay in seconds after start failure prior to retry;
requires StopOnError = 0.
StartFailureTimeout:
Milliseconds to wait before terminating. (0=Wait forever).
StartNoNodeGroupTimeout:
Time to wait for nodes without nodegroup before trying to
start (0=forever).
StartPartialTimeout:
Milliseconds to wait before trying to start without all
nodes. (0=Wait forever).
StartPartitionedTimeout:
Milliseconds to wait before trying to start partitioned.
(0=Wait forever).
StartupStatusReportFrequency:
Frequency of status reports during startup.
StopOnError:
When set to 0, data node automatically restarts and recovers
following node failures.
StringMemory:
Default size of string memory (0 to 100 = % of maximum, 101+
= actual bytes).
TcpBind_INADDR_ANY:
Bind IP_ADDR_ANY so that connections can be made from
anywhere (for autogenerated connections).
TimeBetweenEpochs:
Time between epochs (synchronization used for replication).
TimeBetweenEpochsTimeout:
Timeout for time between epochs. Exceeding causes node
shutdown.
TimeBetweenGlobalCheckpoints:
Time between group commits of transactions to disk.
TimeBetweenGlobalCheckpointsTimeout:
Minimum timeout for group commit of transactions to disk.
TimeBetweenInactiveTransactionAbortCheck:
Time between checks for inactive transactions.
TimeBetweenLocalCheckpoints:
Time between taking snapshots of database (expressed in
base-2 logarithm of bytes).
TimeBetweenWatchDogCheck:
Time between execution checks inside data node.
TimeBetweenWatchDogCheckInitial:
Time between execution checks inside data node (early start
phases when memory is allocated).
TotalSendBufferMemory:
Total memory to use for all transporter send buffers..
TransactionBufferMemory:
Dynamic buffer space (in bytes) for key and attribute data
allocated for each data node.
TransactionDeadlockDetectionTimeout:
Time transaction can spend executing within data node. This
is time that transaction coordinator waits for each data
node participating in transaction to execute request. If
data node takes more than this amount of time, transaction
is aborted.
TransactionInactiveTimeout:
Milliseconds that application waits before executing another
part of transaction. This is time transaction coordinator
waits for application to execute or send another part
(query, statement) of transaction. If application takes too
much time, then transaction is aborted. Timeout = 0 means
that application never times out.
TransactionMemory:
Memory allocated for transactions on each data node.
TwoPassInitialNodeRestartCopy:
Copy data in 2 passes during initial node restart, which
enables multithreaded building of ordered indexes for such
restarts.
UndoDataBuffer:
Unused; has no effect.
UndoIndexBuffer:
Unused; has no effect.
UseShm:
Use shared memory connections between this data node and API
node also running on this host.
WatchDogImmediateKill:
When true, threads are immediately killed whenever watchdog
issues occur; used for testing and debugging.
The following parameters are specific to ndbmtd:
AutomaticThreadConfig:
Use automatic thread configuration; overrides any settings
for ThreadConfig and MaxNoOfExecutionThreads, and disables
ClassicFragmentation.
ClassicFragmentation:
When true, use traditional table fragmentation; set false to
enable flexible distribution of fragments among LDMs.
Disabled by AutomaticThreadConfig.
EnableMultithreadedBackup:
Enable multi-threaded backup.
MaxNoOfExecutionThreads:
For ndbmtd only, specify maximum number of execution
threads.
MaxSendDelay:
Maximum number of microseconds to delay sending by ndbmtd.
NoOfFragmentLogParts:
Number of redo log file groups belonging to this data node.
NumCPUs:
Specify number of CPUs to use with AutomaticThreadConfig.
PartitionsPerNode:
Determines the number of table partitions created on each
data node; not used if ClassicFragmentation is enabled.
ThreadConfig:
Used for configuration of multithreaded data nodes (ndbmtd).
Default is empty string; see documentation for syntax and
other information.