Arbitration
:
How arbitration should be performed to avoid split-brain
issues in the event of node failure.
ArbitrationTimeout
:
Maximum time (milliseconds) database partition waits for
arbitration signal
BackupDataBufferSize
:
Default size of databuffer for a backup (in bytes)
BackupDataDir
:
Path to where to store backups. Note that the string
'/BACKUP' is always appended to this setting, so that the
*effective* default is FileSystemPath/BACKUP.
BackupDiskWriteSpeedPct
:
Sets the percentage of the data node's allocated maximum
write speed (MaxDiskWriteSpeed) to reserve for LCPs when
starting abackup.
BackupLogBufferSize
:
Default size of log buffer for a 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 the number of lock records for scan with
hold lock
BuildIndexThreads
:
Number of threads to use for building ordered indexes during
a 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 a
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. Intended primarily
for upgrades and downgrades to and from NDB 7.2.7+; see the
documentation before attempting to use.
DictTrace
:
Enable DBDICT debugging; for NDB development
DiskCheckpointSpeed
:
Bytes allowed to be written by checkpoint, per second
DiskCheckpointSpeedInRestart
:
Bytes allowed to be written by checkpoint during restart,
per second
DiskIOThreadPool
:
Number of unbound threads for file access (currently only
for Disk Data); known as IOThreadPool before MySQL Cluster
NDB 6.4.3.
Diskless
:
Run without using the disk
DiskPageBufferEntries
:
Number of 32K page entries to allocate in
DiskPageBufferMemory. Very large disk transactions may
require increasing this value.
DiskPageBufferMemory
:
Number of bytes on each data node allocated for the disk
page buffer cache
DiskSyncSize
:
Amount of data written to file before a synch is forced
EventLogBufferSize
:
Size of circular buffer for NDB log events within data
nodes.
ExecuteOnComputer
:
String referencing an 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 the data node stores its data
(directory must exist)
FileSystemPathDataFiles
:
Path to directory where the data node stores its Disk Data
files. The default value is FilesystemPathDD, if set;
otherwise, FilesystemPath is used if it is set; otherwise,
the value of DataDir is used.
FileSystemPathDD
:
Path to directory where the data node stores its Disk Data
and undo files. The default value is FileSystemPath, if set;
otherwise, the value of DataDir is used.
FileSystemPathUndoFiles
:
Path to directory where the data node stores its undo files
for Disk Data. The default value is FilesystemPathDD, if
set; otherwise, FilesystemPath is used if it is set;
otherwise, the 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 the order in which data nodes check each others'
heartbeats for determining whether a given node is still
active and connected to the 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.
Id
:
Number identifying the data node (Id). Now deprecated; use
NodeId instead.
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. The value is scaled down by
IndexStatTriggerScale.
IndexStatTriggerScale
:
Scale down IndexStatTriggerPct by this amount, multiplied by
the base 2 logarithm of the index size, for a large index.
Set to 0 to disable scaling.
IndexStatUpdateDelay
:
Minimum delay between automatic index statistics updates for
a given index. 0 means no delay.
InitFragmentLogFiles
:
Initialize fragment logfiles (sparse/full)
InitialLogFileGroup
:
Describes a log file group that is created during an initial
start. See documentation for format.
InitialNoOfOpenFiles
:
Initial number of files open per data node. (One thread is
created per file)
InitialTablespace
:
Describes a tablespace that is created during an initial
start. See documentation for format.
LateAlloc
:
Allocate memory after the connection to the 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.
LockExecuteThreadToCPU
:
In NDB 6.3, the ID of the CPU to run the execution thread;
in NDB 7.0 and later, a comma-delimited list of CPU IDs
LockMaintThreadsToCPU
:
CPU ID indicating which CPU runs the maintenance threads
LockPagesInMainMemory
:
Previously: If set to true/1, then NDB Cluster data is not
swapped out to disk. In MySQL 5.0.36/5.1.15 and later:
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
:
Maximum size of allocation to use when allocating memory for
tables
MaxBufferedEpochs
:
Allowed numbered of epochs that a subscribing node can lag
behind (unprocessed epochs). Exceeding will cause lagging
subscribers to be disconnected.
MaxBufferedEpochBytes
:
Total number of bytes allocated for buffering epochs.
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.
MaxDMLOperationsPerTransaction
:
Limit size of a transaction; aborts the transaction if it
requires more than this many DML operations. Set to 0 to
disable.
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 a 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 the data
node
MaxNoOfConcurrentSubOperations
:
Maximum number of concurrent subscriber operations
MaxNoOfConcurrentTransactions
:
Maximum number of transactions executing concurrently on
this data node, the total number of transactions that can be
executed concurrently is this value times the number of data
nodes in the 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 the
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 (default 0 = MaxNoOfTables *
2)
MaxNoOfSubscriptions
:
Maximum number of subscriptions (default 0 = MaxNoOfTables)
MaxNoOfTables
:
Suggests a total number of NDB tables stored in the database
MaxNoOfTriggers
:
Total number of triggers that can be defined in the system
MaxNoOfUniqueHashIndexes
:
Total number of unique hash indexes that can be defined in
the system
MaxParallelCopyInstances
:
Number of parallel copies during node restarts. Default is
0, which uses number of LDMs on both nodes, to a maximum of
16.
MaxParallelScansPerFragment
:
Maximum number of parallel scans per fragment. Once this
limit is reached, scans are serialized.
MaxStartFailRetries
:
Maximum retries when data node fails on startup, requires
StopOnError = 0. Setting to 0 causes start attempts to
continue indefinitely.
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
:
The percentage of memory resources to keep in reserve for
restarts.
NodeGroup
:
Node group to which the data node belongs; used only during
initial start of cluster.
NodeId
:
Number uniquely identifying the data node among all nodes in
the cluster.
NoOfFragmentLogFiles
:
Number of 16 MB redo log files in each of 4 file sets
belonging to the data node
NoOfReplicas
:
Number of copies of all data in database; recommended value
is 2 (default). Values greater than 2 are not supported in
production.
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.
RealtimeScheduler
:
When true, data node threads are scheduled as real-time
threads. Default is false.
RedoBuffer
:
Number 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 the current redo buffer takes longer
than this many seconds, the number of times that this has
happened is compared to RedoOverCommitCounter.
ReservedSendBufferMemory
:
This parameter is present in NDB code but is not enabled,
and is now deprecated.
RestartOnErrorInsert
:
Control the type of restart caused by inserting an error
(when StopOnError is enabled)
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
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 a 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, the 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 will cause node
shutdown.
TimeBetweenGlobalCheckpoints
:
Time between doing group commit 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 the database (expressed in
base-2 logarithm of bytes)
TimeBetweenWatchDogCheck
:
Time between execution checks inside a data node
TimeBetweenWatchDogCheckInitial
:
Time between execution checks inside a 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 a data node.
This is the time that the transaction coordinator waits for
each data node participating in the transaction to execute a
request. If the data node takes more than this amount of
time, the transaction is aborted. Prior to MySQL Cluster NDB
6.2.18/6.3.24/7.0.5, values between 50 and 100 were
possible, but were treated as 100.
TransactionInactiveTimeout
:
Milliseconds that the application waits before executing
another part of the transaction. This is the time the
transaction coordinator waits for the application to execute
or send another part (query, statement) of the transaction.
If the application takes too much time, then the transaction
is aborted. Timeout = 0 means that the application never
times out.
TwoPassInitialNodeRestartCopy
:
Copy data in 2 passes during initial node restart, which
enables multithreaded building of ordered indexes for such
restarts.
UndoDataBuffer
:
Number of bytes on each data node allocated for writing data
undo logs
UndoIndexBuffer
:
Number of bytes on each data node allocated for writing
index undo logs