dbbroker

DbBroker Daemon

Data storage is abstracted in the commhub ecosystem. DbBroker handles all data storage requests. It interfaces to an appropriate database engine to provide data storage per the Datastore class.

At present, DbBroker supports MySQL and CSV databases. Future plans include support for SQL Server, Oracle, Postgres, Mongo, Cassandra, and others.

Use the tdbcmd or tdatadump utility to query/change the database from the command line.

Daemon Parameters

DbBroker reads these attributes that originate from the commhub.ini file:

Keyword	Value
dbtypes	Comma separated list of types of DB connections supported. Valid types: csv, ini, mysql, postgresql
dbtype.tables	Comma separated list of table names. Use '*' to allow all tables of the dbtype.
dbtype.tablename.filename	Specifies the file that contains the database table of the type and name specified. This applies to file-based database types only, such as csv.
dbtype.server	The database server hostname to contact for the DB type, such as mysql or postgresql.
dbtype.user	The user id to use to log into the DB.
dbtype.passwd	The password to use to log into the DB.
dbtype.dbname	The DB name to use to log into the DB.
dbtype.dbport	The TCP port to use to log into the DB, if different than default.

Programming API to DbBroker

To use the database, use the Datastore class.

Database Tables

View detailed database tables schemas for these tables:

Messages Sent/Received

DbBroker receives XML data that contains the command and parameters. The XML data varies by command, but the tag cmd contains the command, table contains the table to operate on, and recno contains the relevant record number..

Command	Description
get	Fetch a specific record field
set	Set a specific record field
getrec	Fetch a specific record with all or some of its fields
setrec	Set a specific record with all or some of its fields
create	Create a new table.
open	Open a database table.
assert	Assert a new database table schema.
query	Query a database table.
append	Append a record.
delete	Delete a record.
finfo	Query field information.
tinfo	Query table information.
rinfo	Query record information
ftypes	Query field types.
fids	Query field ids.
lock	Lock a record.
unlock	Unlock a record.
fid	Query field id for a field name.
newfid	Add a field to database table.
newenum	Create a new enumeration for a field.
pack	Pack the database table (if supported).
close	Stop using the database table.
hello	Simple echo test to dbbroker.
quit	Instruct dbbroker to exit.

The XML tags are:

Tag	Description
cmd	The data storage operation requested.
table	The name of the table to manipulate.
recno	The record number to manipulate.
field	The field name.
value	The value of the field.
fields	A comma separated list of fields.
schemafile	A filename that contains a database table schema.
query	A query string.
data	Data to support the operation. (Operation specific.)
type	Field type.
size	Field size in bytes.
enumid	Enumeration id in an enumerated field.
enumname	Enumeration value in an enumerated field.

Messages to commhub

Command	Description
DBResponse	Data storage operation was successful. Payload contains response.
DBError	Data storage operation failed. Payload contains error information.