RAFT System Variables
A detailed reference for the system variables used by the RAFT consensus implementation. These variables configure cluster heartbeat behavior, election timeouts, log management, and flow control
List of RAFT System Variables
raft-candidate-timeout
Initial timeout for candidate waiting for votes during election (milliseconds). Uses exponential backoff up to raft_max_candidate_timeout.
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric (ms)
Range
100 to 4294967295
Default
200
raft-data-dir
Data directory where to store replication logs and other node persistent state.
Command Line
Scope
Global
Dynamic
No
Data Type
String
Range
Default
./
raft-event-store-file-size
Maximum size of single log file in bytes. When a log file reaches this size, a new file is created.
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric (Bytes)
Range
1048576 (1 MB) to 1048576000 (1000 MB)
Default
128MB
raft-event-store-max-memory
Maximum size of the in-memory event store buffer in bytes. Events are cached in memory for faster access before being written to disk.
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric (Bytes)
Range
1048576 (1 MB) to 10485760000 (10000 MB)
Default
32MB
raft-event-store-max-size
Maximum total size of the event store on disk in bytes. Older log files are purged when this limit is exceeded.
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric (Bytes)
Range
1048576 (1 MB) to 1048576000000 (1000000 MB)
Default
512MB
raft-flow-control-drift-limit
Maximum index drift allowed between nodes before flow control throttling activates. When the difference between the slowest and fastest node commit positions exceeds this limit, the leader begins throttling requests.
Command Line
Scope
Global
Dynamic
Yes
Data Type
Numeric
Range
0 to 4294967295
Default
100
raft-flow-control-max-throttle-rate
Maximum request rate (requests per second) to sustain when flow control throttling is active. Lower values provide more aggressive throttling.
Command Line
Scope
Global
Dynamic
Yes
Data Type
Numeric
Range
0 to 4294967295
Default
100
raft-follower-timeout
Time follower waits without leader messages before starting election (milliseconds). Should be significantly larger than raft_heartbeat_timeout to avoid unnecessary elections.
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric (ms)
Range
500 to 4294967295
Default
5000
raft-heartbeat-timeout
Interval at which leader sends heartbeat messages (milliseconds). Shorter intervals provide faster failure detection but increase network traffic.
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric (ms)
Range
100 to 4294967295
Default
1000
raft-listen-port
Port to listen for incoming cluster connections.
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric (Port)
Range
0 to 65535
Default
50002
raft-log-filter
In order to reduce amount of logging on DEBUG level, this filter can be used to select output from specific operations. The format is comma separated list of strings, e.g. 'rvc_send,rvc_recv'. The actual useful values for filter depend on underlying Craft implementation and is subject to change.
Command Line
Scope
Global
Dynamic
Yes
Data Type
String
Range
Default
admin,client,server,replication_service
raft-log-level
Verbosity level for logging. Supported values are ERROR, WARN, INFO and DEBUG. The DEBUG setting may get very verbose, so it should be used sparingly (see also raft_log_filter).
Command Line
Scope
Global
Dynamic
Yes
Data Type
Enumeration
Range
ERROR, WARN, INFO, DEBUG
Default
INFO
raft-max-candidate-timeout
Maximum candidate timeout after exponential backoff (milliseconds). Limits how long a candidate will wait between election attempts.
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric (ms)
Range
100 to 4294967295
Default
1500
raft-max-reconnect-attempts
Number of attempts to reconnect to the cluster after ending up in non-primary state.
Command Line
Scope
Global
Dynamic
Yes
Data Type
Numeric
Range
1 to 4294967295
Default
5
raft-node-id
Unique node identifier. The identifier can be either a human-readable string up to 15 characters long or a UUID. If human-readable name is used, it must be unique within the cluster. If another node with the same name already exists in the cluster, the newly added node will fail connecting the cluster. The special value 'auto' is reserved for generating a UUID whenever the server starts from a clean state. This is mainly useful for test scenarios where the grastate.dat is removed, and the node is expected to rejoin the cluster before the previous instance is evicted from the group.
Command Line
Scope
Global
Dynamic
No
Data Type
String
Range
Human-readable string (max 15 chars) or UUID
Default
auto
raft-node-weight
Node weight for replication and voting quorum. The default weight is 1, all nodes in the cluster have the same weight in voting and replication.
PRODUCTION WARNING: Using unequal weights in a cluster is unsafe for production workloads. Weighted quorum does not guarantee that data is replicated on the majority of servers before log events are committed on the leader, which can lead to data loss scenarios. This setting is mainly useful for testing and should not be used in production.
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric
Range
1 to 256
Default
1
raft-non-primary-timeout
Timeout after which the node is considered to be in non-primary state. If no replication events appear in the log within this time period, the node will be considered to be in non-primary state (seconds).
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric (seconds)
Range
1 to 4294967295
Default
20
raft-session-timeout
Timeout after which session to replication system is considered expired if there is no activity. If the node cannot communicate with the leader within this time period, it will be evicted from the cluster (seconds).
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric (seconds)
Range
1 to 4294967295
Default
15
raft-sst-listen-port
Port to listen for SST requests.
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric (Port)
Range
0 to 65535
Default
50001
raft-have-ssl
Indicates whether SSL/TLS is enabled for cluster communication. Possible values are YES, NO, DISABLED, or VERIFY_PEER. This is a read-only variable that reflects the current SSL state.
Command Line
Scope
Global
Dynamic
No
Data Type
Enumeration
Range
YES, NO, DISABLED, VERIFY_PEER
Default
NO
raft-ssl-key
Path to the SSL private key file in PEM format. This variable is read-only and must be set at server startup.
Command Line
Scope
Global
Dynamic
No
Data Type
String
Range
Default
(empty)
raft-ssl-cert
Path to the SSL certificate file in PEM format. This variable is read-only and must be set at server startup.
Command Line
Scope
Global
Dynamic
No
Data Type
String
Range
Default
(empty)
raft-ssl-ca
Path to the CA certificate file in PEM format used to verify peer certificates. This variable is read-only and must be set at server startup.
Command Line
Scope
Global
Dynamic
No
Data Type
String
Range
Default
(empty)
raft-ssl-capath
Path to a directory containing CA certificate files in PEM format. This variable is read-only and must be set at server startup.
Command Line
Scope
Global
Dynamic
No
Data Type
String
Range
Default
(empty)
raft-ssl-cipher
OpenSSL cipher list for TLS 1.2 and below. Uses OpenSSL cipher string format. This variable is read-only and must be set at server startup.
Command Line
Scope
Global
Dynamic
No
Data Type
String
Range
Default
(empty)
raft-ssl-crl
Path to the Certificate Revocation List (CRL) file. This variable is read-only and must be set at server startup.
Command Line
Scope
Global
Dynamic
No
Data Type
String
Range
Default
(empty)
raft-ssl-crlpath
Path to a directory containing Certificate Revocation List files. This variable is read-only and must be set at server startup.
Command Line
Scope
Global
Dynamic
No
Data Type
String
Range
Default
(empty)
raft-tls-version
Comma-separated list of allowed TLS protocol versions. Supported values include TLSv1.2 and TLSv1.3. Default includes both TLSv1.2 and TLSv1.3. This variable is read-only and must be set at server startup.
Command Line
Scope
Global
Dynamic
No
Data Type
String
Range
TLSv1.2, TLSv1.3
Default
TLSv1.2,TLSv1.3
raft-ssl-ciphersuites
List of permitted TLS 1.3 ciphersuites. This is separate from raft_ssl_cipher which applies to earlier TLS versions. This variable is read-only and must be set at server startup.
Command Line
Scope
Global
Dynamic
No
Data Type
String
Range
Default
(empty)
raft-ssl-verify-depth
Maximum depth for certificate chain verification. This variable is read-only and must be set at server startup.
Command Line
Scope
Global
Dynamic
No
Data Type
Numeric
Range
0 to 4294967295
Default
9
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