"createIntegrationTable"
JSON hub "createIntegrationTable action creates a new integration table in FairCom Edge
The "createIntegrationTable" action creates an integration table.
The
"createIntegrationTable"action creates an integration table.This means that it will have the automatically-added integration fields discussed in the Integration fields section, in addition to the fields you explicitly add yourself using the fields property.
If the table already exists, it returns or logs an error.
Integration tables are created with input and read privileges only. This enables them for audit trail purposes. Allowing updates and deletions would destroy audit integrity.
Request examples
Minimal request
{
"api": "hub",
"authToken": "anAuthorizationTokenFromTheServer",
"action": "createIntegrationTable",
"params": {
"tableName": "test1"
}
}{
"api": "hub",
"apiVersion": "1.0",
"requestId": "2",
"authToken": "anAuthorizationTokenFromTheServer",
"action": "createIntegrationTable",
"params": {
"databaseName": "faircom",
"tableName": "test2",
"fields": [
{
"name": "t10",
"type": "VARCHAR",
"length": 128,
"nullable": true
}
],
"metadata": { },
"retentionPeriod": 4,
"retentionUnit": "week"
},
"apiVersion": "1.0",
"debug": "max"
}{
"result": {},
"requestId": "1",
"errorCode": 0,
"errorMessage": ""
}{
"authToken": "anAuthorizationTokenFromTheServer",
"result": {},
"requestId": "2",
"debugInfo": {
"request": {
"authToken": "anAuthorizationTokenFromTheServer",
"api": "hub",
"action": "createIntegrationTable",
"params": {
"databaseName": "faircom",
"tableName": "test1",
"fields": [
{
"name": "t10",
"type": "VARCHAR",
"length": 128,
"nullable": true
}
],
"metadata": {},
"retentionPeriod": 4,
"retentionUnit": "week"
},
"apiVersion": "1.0",
"requestId": "2",
"debug": "max"
}
},
"errorCode": 12020,
"errorMessage": "Not able to create integration table [test1]. Integration table name already exists."
}Use the createIntegrationTable JSON API action to create a new integration table in FairCom Edge
The "params" property is an object that contains an action's parameters. Each action defines its own required and optional properties.
Properties summary
"params" properties summaryProperty | Description | Default | Type | Limits (inclusive) | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
specifies the name of a database | Defaults to the | string | 1 to 64 bytes | ||||||||||||||||||||||
contains objects that specify the settings of a field in a table | Not required - No default value | array | |||||||||||||||||||||||
| controls when and how the server automatically sets the field value |
| string |
| |||||||||||||||||||||
| specifies the default value of a field |
| string | 0 to 65,500 bytes | |||||||||||||||||||||
| specifies the length of a field's value in a record |
| integer |
| |||||||||||||||||||||
| specifies a new name of the field | required | string | 0 to 64 bytes | |||||||||||||||||||||
| allows a field to contain a NULL value when |
| Boolean |
| |||||||||||||||||||||
| adds a field to the specified ordinal position of the table's primary key when > 0 |
| integer |
| |||||||||||||||||||||
| specifies the number of places to the right of the decimal point |
| integer |
| |||||||||||||||||||||
| specifies the type of field | required | string |
| |||||||||||||||||||||
exists primarily for the user interface to find integration information |
| object | May contain any number and type of user-defined properties | ||||||||||||||||||||||
controls how messages are persisted |
| string |
| ||||||||||||||||||||||
specifies the number of retention units, which controls how long data is retained – see |
| integer |
| ||||||||||||||||||||||
purges expired messages each time this unit cycles – see |
| string |
| ||||||||||||||||||||||
specifies the variant type format of the |
| string |
| ||||||||||||||||||||||
specifies the name of a table | Required - No default value | string | 1 to 64 bytes |
The "databaseName" property is an optional string that specifies the database that contains the tables. It defaults to the database name supplied at login.
Note
In the API Explorer, "defaultDatabaseName" is set to "ctreeSQL" in the "createSession" action that happens at login.
A zero-length
"databaseName"is invalid.Its limits are from 0 to 64 bytes.
If the
"databaseName"property is omitted or set tonull, the server will use the default database name specified at login.If no default database is specified during
"createSession","defaultDatabaseName"will be set to the"defaultDatabaseName"value that is specified in theservices.jsonfile.
The "fields" property is a required array of field-type objects. There is one object for each top-level field in the array. Each object identifies the actual data type of the field as stored in the database.
A field-type object is used when creating a table. It contains one object for each field definition returned in the data.
Full request example
"fields":
[
{
"name": "name",
"type": "varchar",
"length": 50,
"scale": null,
"defaultValue": null,
"nullable": false,
"primaryKey":1
}
]Full response example
"fields":
[
{
"name": "id",
"type": "bigint",
"length": null,
"scale": null,
"autoValue": "none",
"defaultValue": null,
"nullable": false,
"primaryKey": 1
}
]The "metadata" property is an optional JSON object. It exists primarily for the user interface to find integration information. By default, it is an empty JSON object.
It contains a flexible set of properties.
It typically contains tags and description properties.
Example
{
"description": "",
"tags": [""],
"yourOwnProperties": "usage, purpose, notes, location, etc.",
}
The "retentionPolicy" property controls how messages are persisted. This property is optional.
If not specified, the default found in the services.json file is used. Initially, it is "autoPurge".
retentionPolicy values:"autoPurge"This is the default. It is automatically applied when a new topic is created. It is preferred because it allows FairCom's servers to automatically remove messages that are older than the retention time. This helps ensure message data does not consume all storage space. It also minimizes storage costs and speeds up data access. The server partitions a table into multiple files so it can efficiently delete expired files.
"neverPurge"This stores messages on disk and never removes them. This is useful when you need the entire history of the message stream. If message velocity is high, this can consume all storage space and cause an outage. The server creates a non-partitioned table, which is slightly faster than a partitioned table because it stores all records in one file.
"doNotPersist"This stores messages only in RAM, where they are transmitted more quickly. Undelivered messages are lost when FairCom's servers stop and restart. No transforms can be applied to the payload. Message data cannot be bridged across protocols.
Important
Changing the "retentionPolicy" property value to "doNotPersist" removes all existing message history for the topic because it changes how messages are stored on disk.
The "retentionPeriod" property specifies how many units of data to retain. It must be an integer value from 1 to 100. It refers to the unit of time specified by the "retentionUnit" property — for example, if "retentionPeriod" is 14 and "retentionUnit" is "day", then message data is retained for 14 days. This property is optional.
If not specified, the default found in the services.json file is used. Initially, it is 4 (weeks).
Automatically purging data is important to ensure that retained data does not consume all storage and shut down the computer. The default value of 4 weeks allows FairCom's servers to store 1 TB of messages when 200 topics send one 2K message per second.
Note
If the value is not an integer from
1to100, FairCom's servers set it to the default value.Smaller numbers improve SQL performance.
Each time the
"retentionPeriod"cycles, FairCom's servers automatically and efficiently delete expired data.FairCom's servers only use the
"retentionPeriod"property when the"retentionPolicy"is"autoPurge".The
"retentionPeriod"can be changed to retain fewer or more messages. Changing it does not necessarily destroy existing data, but data may expire more quickly or be retained longer.The
"retentionPeriod"and"retentionUnit"properties control data granularity as well as the retention time. In other words,"retentionPeriod"defines how many sets of data are stored, and"retentionUnit"defines how often data is purged.For example, if
"rententionPeriod"is set to14, the server stores 14 sets of data. At the beginning of the 15th cycle, the server automatically purges the oldest set of data. If"retentionUnit"is set today, then data will be purged daily. If set to"week", then data will be purged weekly.The current calendar date affects purging.
FairCom's servers automatically purge all retained data that has expired. This is noticeable when FairCom's servers come online after having been offline for a long time. When a server comes back online, it automatically purges all expired data.
For example, if a FairCom server is offline for four weeks when it comes online, it will completely purge all retained data that has a retention time of less than 4 weeks.
Each time this unit cycles, FairCom purges expired messages. For example, if you want a week's worth of messages to be purged once a week, set "retentionUnit" to "week" . This property is optional.
If not specified, the default found in the services.json file is used. Initially, it is "week".
This property is used in concert with
"retentionPeriod"to determine retention time."retentionUnit"values:"minute""hour""day""week""month""year""forever"
Note
For best performance, set the
"retentionUnit"to a value that keeps"retentionPeriod"between5and30.When you set
"retentionUnit"property to"forever"the server does not purge messages. This setting is the same as setting"retentionPolicy"to"neverPurge".FairCom MQ only uses the
"retentionUnit"property when the"retentionPolicy"is"autoPurge".
The "sourcePayloadFormat" property is an optional string that defines the variant type format of the "source_payload" field. When omitted or set to null, it defaults to "binary".
This property is a string containing the following enumerated values:
"binary""json""utf8""siemensUDT""jpeg""xml"
This property is a hint to the server about the format and type of the MQTT message payload.
This property does not cause server to validate the MQTT payload to see if it matches the type you set. The server stores the payload as is without validation. For example, if you set the type to
"json", it does not stop the server from receiving and storing a non-JSON value or invalid JSON document in the source payload.The FairCom Edge Explorer application may use the value of this property to determine the default way to display a topic's payload.
The transform engine may use the value of this property to help it transform the source payload.
The "tableName" property contains the name of the table in the database where the event occurred. It is a non-zero-length string.
A table name may contain up to 64 ASCII characters and must not start with a number.
A table in DBnotify is defined by "databaseName", "ownerName" and "tableName" or by "dataFilePath".
This property controls when and how the server automatically sets the field value.
Specify only one of these values per field.
"none"indicates the server does not automatically set the field's value."incrementOnInsert"indicates the server automatically increments a field’s value each time the server inserts a new record. It applies to fields that are of the type of decimal or one of the integer types, such as"bigint". Only one field per table can have this attribute. The server returns an error when assigning this attribute to multiple fields. The JSON DB API automatically creates the"id"field as an"incrementOnInsert"field. If you apply this attribute to another field, it becomes the only automatically incremented field in the table. If you want that field to be the primary key, assign"primaryKey": 1to it."timestampOnInsert"indicates the server automatically sets a field’s value to the current date and time of an insert. It applies only to fields with a type of"timestamp"."timestampOnUpdate"indicates the server automatically sets a field’s value to the current date and time of an update. It applies only to timestamp fields."timestampOnUpdateAndInsert"indicates the server automatically sets a field’s value to the current date and time of an insert and an update. It applies only to fields with a type of"timestamp"."changeId"indicates the server uses the field for optimistic locking. The server automatically sets the field's value to the internal transaction number used during the last update of the record. This value changes each time the server updates the record. A table may only have one change tracking field. The field type must be"bigint".The JSON DB API automatically creates a
"changeid"field with change-tracking functionality.Change tracking is optional in the CTDB and ISAM APIs. The application must create a 64-bit integer field and assign change-tracking functionality to it.