8.1. GQTP

GQTP is the acronym of Groonga Query Transfer Protocol. GQTP is the original protocol for groonga.

8.1.1. Protocol

GQTP is stateful client server model protocol. The following sequence is one processing unit:

• Client sends a request

• Server receives the request

• Server processes the request

• Server sends a response

• Client receives the response

You can do zero or more processing units in a session.

Both request and response consist of GQTP header and body. GQTP header is fixed size data. Body is variable size data and its size is stored in GQTP header. The content of body isn’t defined in GQTP.

8.1.1.1. GQTP header

GQTP header consists of the following unsigned integer values:

Name	Size	Description
protocol	1byte	Protocol type.
query_type	1byte	Content type of body.
key_length	2byte	Not used.
level	1byte	Not used.
flags	1byte	Flags.
status	2byte	Return code.
size	4byte	Body size.
opaque	4byte	Not used.
cas	8byte	Not used.

All header values are encoded by network byte order.

The following sections describes available values of each header value.

The total size of GQTP header is 24byte.

8.1.1.1.1. protocol

The value is always 0xc7 in both request and response GQTP header.

8.1.1.1.2. query_type

The value is one of the following values:

Name	Value	Description
NONE	0	Free format.
TSV	1	Tab Separated Values.
JSON	2	JSON.
XML	3	XML.
MSGPACK	4	MessagePack.

This is not used in request GQTP header.

This is used in response GQTP header. Body is formatted as specified type.

8.1.1.1.3. flags

The value is bitwise OR of the following values:

Name	Value	Description
MORE	0x01	There are more data.
TAIL	0x02	There are no more data.
HEAD	0x04	Not used.
QUIET	0x08	Be quiet.
QUIT	0x10	Quit.

You must specify MORE or TAIL flag.

If you use MORE flag, you should also use QUIET flag. Because you don’t need to show a response for your partial request.

Use QUIT flag to quit this session.

8.1.1.1.4. status

Here are available values. The new statuses will be added in the future.

• 0: SUCCESS

• 1: END_OF_DATA

• 65535: UNKNOWN_ERROR

• 65534: OPERATION_NOT_PERMITTED

• 65533: NO_SUCH_FILE_OR_DIRECTORY

• 65532: NO_SUCH_PROCESS

• 65531: INTERRUPTED_FUNCTION_CALL

• 65530: INPUT_OUTPUT_ERROR

• 65529: NO_SUCH_DEVICE_OR_ADDRESS

• 65528: ARG_LIST_TOO_LONG

• 65527: EXEC_FORMAT_ERROR

• 65526: BAD_FILE_DESCRIPTOR

• 65525: NO_CHILD_PROCESSES

• 65524: RESOURCE_TEMPORARILY_UNAVAILABLE

• 65523: NOT_ENOUGH_SPACE

• 65522: PERMISSION_DENIED

• 65521: BAD_ADDRESS

• 65520: RESOURCE_BUSY

• 65519: FILE_EXISTS

• 65518: IMPROPER_LINK

• 65517: NO_SUCH_DEVICE

• 65516: NOT_A_DIRECTORY

• 65515: IS_A_DIRECTORY

• 65514: INVALID_ARGUMENT

• 65513: TOO_MANY_OPEN_FILES_IN_SYSTEM

• 65512: TOO_MANY_OPEN_FILES

• 65511: INAPPROPRIATE_I_O_CONTROL_OPERATION

• 65510: FILE_TOO_LARGE

• 65509: NO_SPACE_LEFT_ON_DEVICE

• 65508: INVALID_SEEK

• 65507: READ_ONLY_FILE_SYSTEM

• 65506: TOO_MANY_LINKS

• 65505: BROKEN_PIPE

• 65504: DOMAIN_ERROR

• 65503: RESULT_TOO_LARGE

• 65502: RESOURCE_DEADLOCK_AVOIDED

• 65501: NO_MEMORY_AVAILABLE

• 65500: FILENAME_TOO_LONG

• 65499: NO_LOCKS_AVAILABLE

• 65498: FUNCTION_NOT_IMPLEMENTED

• 65497: DIRECTORY_NOT_EMPTY

• 65496: ILLEGAL_BYTE_SEQUENCE

• 65495: SOCKET_NOT_INITIALIZED

• 65494: OPERATION_WOULD_BLOCK

• 65493: ADDRESS_IS_NOT_AVAILABLE

• 65492: NETWORK_IS_DOWN

• 65491: NO_BUFFER

• 65490: SOCKET_IS_ALREADY_CONNECTED

• 65489: SOCKET_IS_NOT_CONNECTED

• 65488: SOCKET_IS_ALREADY_SHUTDOWNED

• 65487: OPERATION_TIMEOUT

• 65486: CONNECTION_REFUSED

• 65485: RANGE_ERROR

• 65484: TOKENIZER_ERROR

• 65483: FILE_CORRUPT

• 65482: INVALID_FORMAT

• 65481: OBJECT_CORRUPT

• 65480: TOO_MANY_SYMBOLIC_LINKS

• 65479: NOT_SOCKET

• 65478: OPERATION_NOT_SUPPORTED

• 65477: ADDRESS_IS_IN_USE

• 65476: ZLIB_ERROR

• 65475: LZO_ERROR

• 65474: STACK_OVER_FLOW

• 65473: SYNTAX_ERROR

• 65472: RETRY_MAX

• 65471: INCOMPATIBLE_FILE_FORMAT

• 65470: UPDATE_NOT_ALLOWED

• 65469: TOO_SMALL_OFFSET

• 65468: TOO_LARGE_OFFSET

• 65467: TOO_SMALL_LIMIT

• 65466: CAS_ERROR

• 65465: UNSUPPORTED_COMMAND_VERSION

8.1.1.1.5. size

The size of body. The maximum body size is 4GiB because size is 4byte unsigned integer. If you want to send 4GiB or more larger data, use MORE flag.

8.1.2. Example

8.1.2.1. How to run a GQTP server

Groonga has a special protocol, named Groonga Query Transfer Protocol (GQTP), for remote access to a database. The following form shows how to run Groonga as a GQTP server.

Form:

groonga [-p PORT_NUMBER] -s DB_PATH

The -s option specifies to run Groonga as a server. DB_PATH specifies the path of the existing database to be hosted. The -p option and its argument, PORT_NUMBER, specify the port number of the server. The default port number is 10043, which is used when you don’t specify PORT_NUMBER.

The following command runs a server that listens on the default port number. The server accepts operations to the specified database.

Execution example:

% groonga -s /tmp/groonga-databases/introduction.db
Ctrl-c
%

8.1.2.2. How to run a GQTP daemon

You can also run a GQTP server as a daemon by using the -d option, instead of the -s option.

Form:

groonga [-p PORT_NUMBER] -d DB_PATH

A Groonga daemon prints its process ID as follows. In this example, the process ID is 12345. Then, the daemon opens a specified database and accepts operations to that database.

Execution example:

% groonga -d /tmp/groonga-databases/introduction.db
12345
%

8.1.2.3. How to run a GQTP client

You can run Groonga as a GQTP client as follows:

Form:

groonga [-p PORT_NUMBER] -c [HOST_NAME_OR_IP_ADDRESS]

This command establishes a connection with a GQTP server and then enters into interactive mode. HOST_NAME_OR_IP_ADDRESS specifies the hostname or the IP address of the server. If not specified, Groonga uses the default hostname “localhost”. The -p option and its argument, PORT_NUMBER, specify the port number of the server. If not specified, Groonga uses the default port number 10043.

Execution example:

$ groonga -c
status
# [
#   [
#     0,
#     1337566253.89858,
#     0.000355720520019531
#   ],
#   {
#     "alloc_count": 29,
#     "starttime": 1696558618,
#     "start_time": 1696558618,
#     "uptime": 0,
#     "version": "2.9.1",
#     "n_queries": 0,
#     "cache_hit_rate": 0.0,
#     "command_version": 1,
#     "default_command_version": 1,
#     "max_command_version": 3,
#     "n_jobs": 0,
#     "features": {
#       "nfkc": true,
#       "mecab": true,
#       "message_pack": true,
#       "mruby": true,
#       "onigmo": true,
#       "zlib": true,
#       "lz4": true,
#       "zstandard": true,
#       "kqueue": false,
#       "epoll": true,
#       "poll": false,
#       "rapidjson": false,
#       "apache_arrow": true,
#       "xxhash": true,
#       "blosc": true,
#       "bfloat16": true,
#       "h3": true,
#       "simdjson": true,
#       "llama.cpp": true,
#       "back_trace": true,
#       "reference_count": false
#     },
#     "apache_arrow": {
#       "version_major": 2,
#       "version_minor": 9,
#       "version_patch": 1,
#       "version": "2.9.1"
#     },
#     "memory_map_size": 2929,
#     "n_workers": 0,
#     "default_n_workers": 0,
#     "os": "Linux",
#     "cpu": "x86_64"
#   }
# ]
> ctrl-d
$

In interactive mode, Groonga reads commands from the standard input and executes them one by one.

8.1.2.4. How to terminate a GQTP server

You can terminate a GQTP server with a shutdown command:

$ groonga -c
> shutdown
$

8.1.3. See also

• groonga executable file

• GQTP