Configuration Parameters

In this chapter, all the configuration parameters on both server and client side are described thoroughly.

Configuration File on Server Side

On the server side, the actual service of TDengine is provided by an executable taosd whose parameters can be configured in file taos.cfg to meet the requirements of different use cases. The default location of taos.cfg is /etc/taos, but can be changed by using -c parameter on the CLI of taosd. For example, the configuration file can be put under /home/user and used like below

taosd -c /home/user

Parameter -C can be used on the CLI of taosd to show its configuration, like below:

taosd -C

Configuration File on Client Side

TDengine CLI taos is the tool for users to interact with TDengine. It can share same configuration file as taosd or use a separate configuration file. When launching taos, parameter -c can be used to specify the location where its configuration file is. For example taos -c /home/cfg means /home/cfg/taos.cfg will be used. If -c is not used, the default location of the configuration file is /etc/taos. For more details please use taos --help to get.

From version 2.0.10.0 below commands can be used to show the configuration parameters of the client side.

taos -C

taos --dump-config

Configuration Parameters

note

taosd needs to be restarted for the parameters changed in the configuration file to take effect.

Connection Parameters

firstEp

Attribute	Description
Applicable	Server and Client
Meaning	The end point of the first dnode in the cluster to be connected to when taosd or taos is started
Default Value	localhost:6030

secondEp

Attribute	Description
Applicable	Server and Client
Meaning	The end point of the second dnode to be connected to if the firstEp is not available when taosd or taos is started
Default Value	None

fqdn

Attribute	Description
Applicable	Server Only
Meaning	The FQDN of the host where taosd will be started. It can be IP address
Default Value	The first hostname configured for the host
Note	It should be within 96 bytes

serverPort

Attribute	Description
Applicable	Server Only
Meaning	The port for external access after taosd is started
Default Value	6030
Note	REST service is provided by taosd before 2.4.0.0 but by taosAdapter after 2.4.0.0, the default port of REST service is 6041

note

TDengine uses 13 continuous ports, both TCP and UDP, starting with the port specified by serverPort. You should ensure, in your firewall rules, that these ports are kept open. Below table describes the ports used by TDengine in details.

Protocol	Default Port	Description	How to configure
TCP	6030	Communication between client and server	serverPort
TCP	6035	Communication among server nodes in cluster	serverPort+5
TCP	6040	Data syncup among server nodes in cluster	serverPort+10
TCP	6041	REST connection between client and server	Prior to 2.4.0.0: serverPort+11; After 2.4.0.0 refer to taosAdapter
TCP	6042	Service Port of Arbitrator	The parameter of Arbitrator
TCP	6043	Service Port of TaosKeeper	The parameter of TaosKeeper
TCP	6044	Data access port for StatsD	refer to taosAdapter
UDP	6045	Data access for statsd	refer to taosAdapter
TCP	6060	Port of Monitoring Service in Enterprise version
UDP	6030-6034	Communication between client and server	serverPort
UDP	6035-6039	Communication among server nodes in cluster	serverPort

maxShellConns

Attribute	Description
Applicable	Server Only
Meaning	The maximum number of connections a dnode can accept
Value Range	10-50000000
Default Value	5000

maxConnections

Attribute	Description
Applicable	Server Only
Meaning	The maximum number of connections allowed by a database
Value Range	1-100000
Default Value	5000
Note	The maximum number of worker threads on the client side is maxConnections/100

rpcForceTcp

Attribute	Description
Applicable	Server and Client
Meaning	TCP is used by force
Value Range	0: disabled 1: enabled
Default Value	0
Note	It's suggested to configure to enable if network is not good enough

Monitoring Parameters

monitor

Attribute	Description
Applicable	Server Only
Meaning	The switch for monitoring inside server. The workload of the hosts, including CPU, memory, disk, network, TTP requests, are collected and stored in a system builtin database LOG
Value Range	0: monitoring disabled, 1: monitoring enabled
Default Value	1

monitorInterval

Attribute	Description
Applicable	Server Only
Meaning	The interval of collecting system workload
Unit	second
Value Range	1-600
Default Value	30

telemetryReporting

Attribute	Description
Applicable	Server Only
Meaning	Switch for allowing TDengine to collect and report service usage information
Value Range	0: Not allowed; 1: Allowed
Default Value	1

Query Parameters

queryBufferSize

Attribute	Description
Applicable	Server Only
Meaning	The total memory size reserved for all queries
Unit	MB
Default Value	None
Note	It can be estimated by "maximum number of concurrent queries" _ "number of tables" _ 170

ratioOfQueryCores

Attribute	Description
Applicable	Server Only
Meaning	Maximum number of query threads
Default Value	1
Note	value range: float number between [0, 2] 0: only 1 query thread; >0: the times of the number of cores

maxNumOfDistinctRes

Attribute	Description
Applicable	Server Only
Meaning	The maximum number of distinct rows returned
Value Range	[100,000 - 100,000,000]
Default Value	100,000
Note	After version 2.3.0.0

maxSqlGroups

| 属性 | 说明 | | -------- | -------------------------------- | --- | | 适用范围 | Server and Client | | 含义 | The maximus number of groups when group by or interval | | 取值范围 | [500,000 - 10,000,000] | | 缺省值 | 1,000,000 | | 补充说明 | After version 2.6.0.21 | |

Locale Parameters

timezone

Attribute	Description
Applicable	Server and Client
Meaning	TimeZone
Default Value	TimeZone configured in the host

info

To handle the data insertion and data query from multiple timezones, Unix Timestamp is used and stored in TDengine. The timestamp generated from any timezones at same time is same in Unix timestamp. To make sure the time on client side can be converted to Unix timestamp correctly, the timezone must be set properly.

On Linux system, TDengine clients automatically obtain timezone from the host. Alternatively, the timezone can be configured explicitly in configuration file taos.cfg like below.

timezone UTC-7
timezone GMT-8
timezone Asia/Shanghai

The above examples are all proper configuration for the timezone of UTC+8. On Windows system, however, timezone Asia/Shanghai is not supported, it must be set as timezone UTC-8.

The setting for timezone impacts strings that are not in Unix timestamp format and keywords or functions related to date/time. For example:

SELECT count(*) FROM table_name WHERE TS<'2019-04-11 12:01:08';

If the timezone is UTC+8, the above SQL statement is equal to:

SELECT count(*) FROM table_name WHERE TS<1554955268000;

If the timezone is UTC, it's equal to

SELECT count(*) FROM table_name WHERE TS<1554984068000;

To avoid the problems of using time strings, Unix timestamp can be used directly. Furthermore, time strings with timezone can be used in SQL statements. For example "2013-04-12T15:52:01.123+08:00" in RFC3339 format or "2013-04-12T15:52:01.123+0800" in ISO-8601 format are not influenced by timezone setting when converted to Unix timestamp.

locale

Attribute	Description
Applicable	Server and Client
Meaning	Location code
Default Value	Locale configured in host

info

A specific type "nchar" is provided in TDengine to store non-ASCII characters such as Chinese, Japanese, and Korean. The characters to be stored in nchar type are firstly encoded in UCS4-LE before sending to server side. To store non-ASCII characters correctly, the encoding format of the client side needs to be set properly.

The characters input on the client side are encoded using the default system encoding, which is UTF-8 on Linux, or GB18030 or GBK on some systems in Chinese, POSIX in docker, CP936 on Windows in Chinese. The encoding of the operating system in use must be set correctly so that the characters in nchar type can be converted to UCS4-LE.

The locale definition standard on Linux is: <Language>_<Region>.<charset>, for example, in "zh_CN.UTF-8", "zh" means Chinese, "CN" means China mainland, "UTF-8" means charset. On Linux and Mac OSX, the charset can be set by locale in the system. On Windows system another configuration parameter charset must be used to configure charset because the locale used on Windows is not POSIX standard. Of course, charset can also be used on Linux to specify the charset.

charset

Attribute	Description
Applicable	Server and Client
Meaning	Character
Default Value	charset set in the system

info

On Linux, if charset is not set in taos.cfg, when taos is started, the charset is obtained from system locale. If obtaining charset from system locale fails, taos would fail to start. So on Linux system, if system locale is set properly, it's not necessary to set charset in taos.cfg. For example:

locale zh_CN.UTF-8

On a Linux system, if the charset contained in locale is not consistent with that set by charset, the later setting in the configuration file takes precedence.

locale zh_CN.UTF-8
charset GBK

charset GBK
locale zh_CN.UTF-8

On Windows system, it's not possible to obtain charset from system locale. If it's not set in configuration file taos.cfg, it would be default to CP936, same as set as below in taos.cfg. For example

charset CP936

Storage Parameters

dataDir

Attribute	Description
Applicable	Server Only
Meaning	All data files are stored in this directory
Default Value	/var/lib/taos

cache

Attribute	Description
Applicable	Server Only
Meaning	The size of each memory block
Unit	MB
Default Value	16

blocks

Attribute	Description
Applicable	Server Only
Meaning	The number of memory blocks of size cache used by each vnode
Default Value	6

days

Attribute	Description
Applicable	Server Only
Meaning	The time range of the data stored in single data file
Unit	day
Default Value	10

keep

Attribute	Description
Applicable	Server Only
Meaning	The number of days for data to be kept
Unit	day
Default Value	3650

minRows

Attribute	Description
Applicable	Server Only
Meaning	minimum number of rows in single data file
Default Value	100

maxRows

Attribute	Description
Applicable	Server Only
Meaning	maximum number of rows in single data file
Default Value	4096

walLevel

Attribute	Description
Applicable	Server Only
Meaning	WAL level
Value Range	0: wal disabled 1: wal enabled without fsync 2: wal enabled with fsync
Default Value	1

fsync

Attribute	Description
Applicable	Server Only
Meaning	The waiting time for invoking fsync when walLevel is 2
Unit	millisecond
Value Range	0: no waiting time, fsync is performed immediately once WAL is written; maximum value is 180000, i.e. 3 minutes
Default Value	3000

update

Attribute	Description
Applicable	Server Only
Meaning	If it's allowed to update existing data
Value Range	0: not allowed 1: a row can only be updated as a whole 2: a part of columns can be updated
Default Value	0
Note	Not available from version 2.0.8.0

cacheLast

Attribute	Description
Applicable	Server Only
Meaning	Whether to cache the latest rows of each sub table in memory
Value Range	0: not cached 1: the last row of each sub table is cached 2: the last non-null value of each column is cached 3: identical to both 1 and 2 are set
Default Value	0

minimalTmpDirGB

Attribute	Description
Applicable	Server and Client
Meaning	When the available disk space in tmpDir is below this threshold, writing to tmpDir is suspended
Unit	GB
Default Value	1.0

minimalDataDirGB

Attribute	Description
Applicable	Server Only
Meaning	hen the available disk space in dataDir is below this threshold, writing to dataDir is suspended
Unit	GB
Default Value	2.0

vnodeBak

Attribute	Description
Applicable	Server Only
Meaning	Whether to backup the corresponding vnode directory when a vnode is deleted
Value Range	0: not backed up, 1: backup
Default Value	1

Cluster Parameters

numOfMnodes

Attribute	Description
Applicable	Server Only
Meaning	The number of management nodes
Default Value	3

replica

Attribute	Description
Applicable	Server Only
Meaning	The number of replications
Value Range	1-3
Default Value	1

quorum

Attribute	Description
Applicable	Server Only
Meaning	The number of required confirmations for data replication in case of multiple replications
Value Range	1,2
Default Value	1

role

Attribute	Description
Applicable	Server Only
Meaning	The role of the dnode
Value Range	0: both mnode and vnode 1: mnode only 2: dnode only
Default Value	0

balance

Attribute	Description
Applicable	Server Only
Meaning	Automatic load balancing
Value Range	0: disabled, 1: enabled
Default Value	1

balanceInterval

Attribute	Description
Applicable	Server Only
Meaning	The interval for checking load balance by mnode
Unit	second
Value Range	1-30000
Default Value	300

arbitrator

Attribute	Description
Applicable	Server Only
Meaning	End point of arbitrator, format is same as firstEp
Default Value	None

Time Parameters

precision

Attribute	Description
Applicable	Server only
Meaning	Time precision used for each database
Value Range	ms: millisecond; us: microsecond ; ns: nanosecond
Default Value	ms

rpcTimer

Attribute	Description
Applicable	Server and Client
Meaning	rpc retry interval
Unit	milliseconds
Value Range	100-3000
Default Value	300

rpcMaxTime

Attribute	Description
Applicable	Server and Client
Meaning	maximum wait time for rpc response
Unit	second
Value Range	100-7200
Default Value	600

statusInterval

Attribute	Description
Applicable	Server Only
Meaning	the interval of dnode reporting status to mnode
Unit	second
Value Range	1-10
Default Value	1

shellActivityTimer

Attribute	Description
Applicable	Server and Client
Meaning	The interval for taos shell to send heartbeat to mnode
Unit	second
Value Range	1-120
Default Value	3

tableMetaKeepTimer

Attribute	Description
Applicable	Server Only
Meaning	The expiration time for metadata in cache, once it's reached the client would refresh the metadata
Unit	second
Value Range	1-8640000
Default Value	7200

maxTmrCtrl

Attribute	Description
Applicable	Server and Client
Meaning	Maximum number of timers
Unit	None
Value Range	8-2048
Default Value	512

offlineThreshold

Attribute	Description
Applicable	Server Only
Meaning	The expiration time for dnode online status, once it's reached before receiving status from a node, the dnode becomes offline
Unit	second
Value Range	5-7200000
Default Value	86400*10 (i.e. 10 days)

Performance Optimization Parameters

numOfThreadsPerCore

Attribute	Description
Applicable	Server and Client
Meaning	The number of consumer threads per CPU core
Default Value	1.0

ratioOfQueryThreads

Attribute	Description
Applicable	Server Only
Meaning	Maximum number of query threads
Value Range	0: Only one query thread 1: Same as number of CPU cores 2: two times of CPU cores
Default Value	1
Note	This value can be a float number, 0.5 means half of the CPU cores

maxVgroupsPerDb

Attribute	Description
Applicable	Server Only
Meaning	Maximum number of vnodes for each DB
Value Range	0-8192
Default Value

maxTablesPerVnode

Attribute	Description
Applicable	Server Only
Meaning	Maximum number of tables in each vnode
Default Value	1000000

minTablesPerVnode

Attribute	Description
Applicable	Server Only
Meaning	Minimum number of tables in each vnode
Default Value	1000

tableIncStepPerVnode

Attribute	Description
Applicable	Server Only
Meaning	When minTablesPerVnode is reached, the number of tables are allocated for a vnode each time
Default Value	1000

maxNumOfOrderedRes

Attribute	Description
Applicable	Server and Client
Meaning	Maximum number of rows ordered for a STable
Default Value	100,000

mnodeEqualVnodeNum

Attribute	Description
Applicable	Server Only
Meaning	The number of vnodes whose system resources consumption are considered as equal to single mnode
Default Value	4

numOfCommitThreads

Attribute	Description
Applicable	Server Only
Meaning	Maximum of threads for committing to disk
Default Value

Compression Parameters

comp

Attribute	Description
Applicable	Server Only
Meaning	Whether data is compressed
Value Range	0: uncompressed, 1: One phase compression, 2: Two phase compression
Default Value	2

tsdbMetaCompactRatio

Attribute	Description
Meaning	The threshold for percentage of redundant in meta file to trigger compression for meta file
Value Range	0: no compression forever, [1-100]: The threshold percentage
Default Value	0

compressMsgSize

Attribute	Description
Applicable	Server Only
Meaning	The threshold for message size to compress the message..
Unit	bytes
Value Range	0: already compress; >0: compress when message exceeds it; -1: always uncompress
Default Value	-1

compressColData

Attribute	Description
Applicable	Server Only
Meaning	The threshold for size of column data to trigger compression for the query result
Unit	bytes
Value Range	0: always compress; >0: only compress when the size of any column data exceeds the threshold; -1: always uncompress
Default Value	-1
Note	available from version 2.3.0.0

lossyColumns

Attribute	Description
Applicable	Server Only
Meaning	The floating number types for lossy compression
Value Range	"": lossy compression is disabled float: only for float double: only for double float | double: for both float and double
Default Value	"" , i.e. disabled

fPrecision

Attribute	Description
Applicable	Server Only
Meaning	Compression precision for float type
Value Range	0.1 ~ 0.00000001
Default Value	0.00000001
Note	The fractional part lower than this value will be discarded

dPrecision

Attribute	Description
Applicable	Server Only
Meaning	Compression precision for double type
Value Range	0.1 ~ 0.0000000000000001
Default Value	0.0000000000000001
Note	The fractional part lower than this value will be discarded

Continuous Query Parameters

stream

Attribute	Description
Applicable	Server Only
Meaning	Whether to enable continuous query
Value Range	0: disabled 1: enabled
Default Value	1

minSlidingTime

Attribute	Description
Applicable	Server Only
Meaning	Minimum sliding time of time window
Unit	millisecond or microsecond , depending on time precision
Value Range	10-1000000
Default Value	10

minIntervalTime

Attribute	Description
Applicable	Server Only
Meaning	Minimum size of time window
Unit	millisecond
Value Range	1-1000000
Default Value	10

maxStreamCompDelay

Attribute	Description
Applicable	Server Only
Meaning	Maximum delay before starting a continuous query
Unit	millisecond
Value Range	10-1000000000
Default Value	20000

maxFirstStreamCompDelay

Attribute	Description
Applicable	Server Only
Meaning	Maximum delay time before starting a continuous query the first time
Unit	millisecond
Value Range	10-1000000000
Default Value	10000

retryStreamCompDelay

Attribute	Description
Applicable	Server Only
Meaning	Delay time before retrying a continuous query
Unit	millisecond
Value Range	10-1000000000
Default Value	10

streamCompDelayRatio

Attribute	Description
Applicable	Server Only
Meaning	The delay ratio, with time window size as the base, for continuous query
Value Range	0.1-0.9
Default Value	0.1

info

To prevent system resource from being exhausted by multiple concurrent streams, a random delay is applied on each stream automatically. maxFirstStreamCompDelay is the maximum delay time before a continuous query is started the first time. streamCompDelayRatio is the ratio for calculating delay time, with the size of the time window as base. maxStreamCompDelay is the maximum delay time. The actual delay time is a random time not bigger than maxStreamCompDelay. If a continuous query fails, retryStreamComDelay is the delay time before retrying it, also not bigger than maxStreamCompDelay.

HTTP Parameters

note

HTTP service was provided by taosd prior to version 2.4.0.0 and is provided by taosAdapter after version 2.4.0.0. The parameters described in this section are only application in versions prior to 2.4.0.0. If you are using any version from 2.4.0.0, please refer to taosAdapter.

http

Attribute	Description
Applicable	Server Only
Meaning	Whether to enable http service
Value Range	0: disabled, 1: enabled
Default Value	1

httpEnableRecordSql

Attribute	Description
Applicable	Server Only
Meaning	Whether to record the SQL invocation through REST interface
Default Value	0: false; 1: true
Note	The resulting files, i.e. httpnote.0/httpnote.1, are located under logDir

httpMaxThreads

Attribute	Description
Applicable	Server Only
Meaning	The number of threads for RESTFul interface.
Default Value	2

restfulRowLimit

Attribute	Description
Applicable	Server Only
Meaning	Maximum number of rows returned each time by REST interface.
Default Value	10240
Note	Maximum value is 10,000,000

httpDBNameMandatory

Attribute	Description
Applicable	Server Only
Meaning	Whether database name is required in URL
Value Range	0:not required, 1: required
Default Value	0
Note	From version 2.3.0.0

Log Parameters

logDir

Attribute	Description
Applicable	Server and Client
Meaning	The directory for writing log files
Default Value	/var/log/taos

minimalLogDirGB

Attribute	Description
Applicable	Server and Client
Meaning	When the available disk space in logDir is below this threshold, writing to log files is suspended
Unit	GB
Default Value	1.0

numOfLogLines

Attribute	Description
Applicable	Server and Client
Meaning	Maximum number of lines in single log file
Default Value	10,000,000

asyncLog

Attribute	Description
Applicable	Server and Client
Meaning	The mode of writing log file
Value Range	0: sync way; 1: async way
Default Value	1

logKeepDays

Attribute	Description
Applicable	Server and Client
Meaning	The number of days for log files to be kept
Unit	day
Default Value	0
Note	When it's bigger than 0, the log file would be renamed to "taosdlog.xxx" in which "xxx" is the timestamp when the file is changed last time

debugFlag

Attribute	Description
Applicable	Server and Client
Meaning	Log level
Value Range	131: INFO/WARNING/ERROR; 135: plus DEBUG; 143: plus TRACE
Default Value	131 or 135, depending on the module

mDebugFlag

Attribute	Description
Applicable	Server Only
Meaning	Log level of mnode
Value Range	same as debugFlag
Default Value	135

dDebugFlag

Attribute	Description
Applicable	Server and Client
Meaning	Log level of dnode
Value Range	same as debugFlag
Default Value	135

sDebugFlag

Attribute	Description
Applicable	Server and Client
Meaning	Log level of sync module
Value Range	same as debugFlag
Default Value	135

wDebugFlag

Attribute	Description
Applicable	Server and Client
Meaning	Log level of WAL module
Value Range	same as debugFlag
Default Value	135

sdbDebugFlag

Attribute	Description
Applicable	Server and Client
Meaning	logLevel of sdb module
Value Range	same as debugFlag
Default Value	135

rpcDebugFlag

Attribute	Description
Applicable	Server and Client
Meaning	Log level of rpc module
Value Range	Same as debugFlag
Default Value

tmrDebugFlag

Attribute	Description
Applicable	Server and Client
Meaning	Log level of timer module
Value Range	Same as debugFlag
Default Value

cDebugFlag

Attribute	Description
Applicable	Client Only
Meaning	Log level of Client
Value Range	Same as debugFlag
Default Value

jniDebugFlag

Attribute	Description
Applicable	Client Only
Meaning	Log level of jni module
Value Range	Same as debugFlag
Default Value

odbcDebugFlag

Attribute	Description
Applicable	Client Only
Meaning	Log level of odbc module
Value Range	Same as debugFlag
Default Value

uDebugFlag

Attribute	Description
Applicable	Server and Client
Meaning	Log level of common module
Value Range	Same as debugFlag
Default Value

httpDebugFlag

Attribute	Description
Applicable	Server Only
Meaning	Log level of http module (prior to 2.4.0.0)
Value Range	Same as debugFlag
Default Value

mqttDebugFlag

Attribute	Description
Applicable	Server Only
Meaning	Log level of mqtt module
Value Range	Same as debugFlag
Default Value

monitorDebugFlag

Attribute	Description
Applicable	Server Only
Meaning	Log level of monitoring module
Value Range	Same as debugFlag
Default Value

qDebugFlag

Attribute	Description
Applicable	Server and Client
Meaning	Log level of query module
Value Range	Same as debugFlag
Default Value

vDebugFlag

Attribute	Description
Applicable	Server and Client
Meaning	Log level of vnode
Value Range	Same as debugFlag
Default Value

tsdbDebugFlag

Attribute	Description
Applicable	Server Only
Meaning	Log level of TSDB module
Value Range	Same as debugFlag
Default Value

cqDebugFlag

Attribute	Description
Applicable	Server and Client
Meaning	Log level of continuous query module
Value Range	Same as debugFlag
Default Value

Client Only

maxSQLLength

Attribute	Description
Applicable	Client Only
Meaning	Maximum length of single SQL statement
Unit	bytes
Value Range	65480-1048576
Default Value	1048576

tscEnableRecordSql

Attribute	Description
Meaning	Whether to record SQL statements in file
Value Range	0: false, 1: true
Default Value	0
Note	The generated files are named as "tscnote-xxxx.0/tscnote-xxx.1" in which "xxxx" is the pid of the client, and located at same place as client log

maxBinaryDisplayWidth

Attribute	Description
Meaning	Maximum display width of binary and nchar in taos shell. Anything beyond this limit would be hidden
Value Range	5 -
Default Value	30

info

If the length of value exceeds maxBinaryDisplayWidth, then the actual display width is max(column name, maxBinaryDisplayLength); otherwise the actual display width is max(length of column name, length of column value). This parameter can also be changed dynamically using set max_binary_display_width <nn\> in TDengine CLI taos.

maxWildCardsLength

Attribute	Description
Meaning	The maximum length for wildcard string used with LIKE
Unit	bytes
Value Range	0-16384
Default Value	100
Note	From version 2.1.6.1

clientMerge

Attribute	Description
Meaning	Whether to filter out duplicate data on client side
Value Range	0: false; 1: true
Default Value	0
Note	From version 2.3.0.0

maxRegexStringLen

Attribute	Description
Meaning	Maximum length of regular expression
Value Range	[128, 16384]
Default Value	128
Note	From version 2.3.0.0

Other Parameters

enableCoreFile

Attribute	Description
Applicable	Server and Client
Meaning	Whether to generate core file when server crashes
Value Range	0: false, 1: true
Default Value	1
Note	The core file is generated under root directory systemctl start taosd is used to start, or under the working directory if taosd is started directly on Linux Shell.