Couchbase is a high performance NoSQL document store that has evolved from the combination of Memcached and CouchDB. The Couchbase binary protocol is based off of the Memcached binary protocol.
This document has been adapted from the Memcached 'Binary Protocol Revamped' document and may make reference to parts of the protocol not implemented by Couchbase Server.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.
General format of a packet:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| HEADER |
| |
| |
| |
+---------------+---------------+---------------+---------------+
24| COMMAND-SPECIFIC EXTRAS (as needed) |
| (note length in the extras length header field) |
+---------------+---------------+---------------+---------------+
m| Key (as needed) |
| (note length in key length header field) |
+---------------+---------------+---------------+---------------+
n| Value (as needed) |
| (note length is total body length header field, minus |
| sum of the extras and key length body fields) |
+---------------+---------------+---------------+---------------+
Total 24 + x bytes (24 byte header, and x byte body)
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| Magic | Opcode | Key length |
+---------------+---------------+---------------+---------------+
4| Extras length | Data type | vbucket id |
+---------------+---------------+---------------+---------------+
8| Total body length |
+---------------+---------------+---------------+---------------+
12| Opaque |
+---------------+---------------+---------------+---------------+
16| CAS |
| |
+---------------+---------------+---------------+---------------+
Total 24 bytes
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| Magic | Opcode | Key Length |
+---------------+---------------+---------------+---------------+
4| Extras length | Data type | Status |
+---------------+---------------+---------------+---------------+
8| Total body length |
+---------------+---------------+---------------+---------------+
12| Opaque |
+---------------+---------------+---------------+---------------+
16| CAS |
| |
+---------------+---------------+---------------+---------------+
Total 24 bytes
- Magic: Magic number identifying the package (See BinaryProtocolRevamped#Magic_Byte)
- Opcode: Command code (See BinaryProtocolRevamped#Command_opcodes)
- Key length: Length in bytes of the text key that follows the command extras
- vbucket id (Request only): The virtual bucket for this command
- Status (Response Only): Status of the response (non-zero on error) (See BinaryProtocolRevamped#Response_Status)
- Extras length: Length in bytes of the command extras
- Data type: Reserved for future use (See BinaryProtocolRevamped#Data_Type)
- Total body length: Length in bytes of extra + key + value
- Opaque: Will be copied back to you in the response
- CAS: Data version check
| Raw | Description |
|---|---|
| 0x80 | Request packet for this protocol version |
| 0x81 | Response packet for this protocol version |
Magic byte / version. For each version of the protocol, we'll use a different request/response value pair. This is useful for protocol analyzers to distinguish the nature of the packet from the direction which it is moving. Note, it is common to run a memcached instance on a host that also runs an application server. Such a host will both send and receive memcache packets.
The version should hopefully correspond only to different meanings of the command byte. In an ideal world, we will not change the header format. As reserved bytes are given defined meaning, the protocol version / magic byte values should be incremented.
Traffic analysis tools are encouraged to identify memcache packets and provide detailed interpretation if the magic bytes are recognized and otherwise to provide a generic breakdown of the packet. Note, that the key and value positions can always be identified even if the magic byte or command opcode are not recognized.
Possible values of this two-byte field:
| Raw | Description |
|---|---|
| 0x0000 | No error |
| 0x0001 | Key not found |
| 0x0002 | Key exists |
| 0x0003 | Value too large |
| 0x0004 | Invalid arguments |
| 0x0005 | Item not stored |
| 0x0006 | Incr/Decr on a non-numeric value |
| 0x0007 | The vbucket belongs to another server |
| 0x0008 | Authentication error |
| 0x0009 | Authentication continue |
| 0x0081 | Unknown command |
| 0x0082 | Out of memory |
| 0x0083 | Not supported |
| 0x0084 | Internal error |
| 0x0085 | Busy |
| 0x0086 | Temporary failure |
Possible values of the one-byte field. See Commands for more information about a given command.
| Raw | Description |
|---|---|
| 0x00 | Get |
| 0x01 | Set |
| 0x02 | Add |
| 0x03 | Replace |
| 0x04 | Delete |
| 0x05 | Increment |
| 0x06 | Decrement |
| 0x07 | Quit |
| 0x08 | Flush |
| 0x09 | GetQ |
| 0x0a | No-op |
| 0x0b | Version |
| 0x0c | GetK |
| 0x0d | GetKQ |
| 0x0e | Append |
| 0x0f | Prepend |
| 0x10 | Stat |
| 0x11 | SetQ |
| 0x12 | AddQ |
| 0x13 | ReplaceQ |
| 0x14 | DeleteQ |
| 0x15 | IncrementQ |
| 0x16 | DecrementQ |
| 0x17 | QuitQ |
| 0x18 | FlushQ |
| 0x19 | AppendQ |
| 0x1a | PrependQ |
| 0x1b | Verbosity |
| 0x1c | Touch |
| 0x1d | GAT |
| 0x1e | GATQ |
| 0x20 | SASL list mechs |
| 0x21 | SASL Auth |
| 0x22 | SASL Step |
| 0x30 | RGet |
| 0x31 | RSet |
| 0x32 | RSetQ |
| 0x33 | RAppend |
| 0x34 | RAppendQ |
| 0x35 | RPrepend |
| 0x36 | RPrependQ |
| 0x37 | RDelete |
| 0x38 | RDeleteQ |
| 0x39 | RIncr |
| 0x3a | RIncrQ |
| 0x3b | RDecr |
| 0x3c | RDecrQ |
| 0x3d | Set VBucket |
| 0x3e | Get VBucket |
| 0x3f | Del VBucket |
| 0x40 | TAP Connect |
| 0x41 | TAP Mutation |
| 0x42 | TAP Delete |
| 0x43 | TAP Flush |
| 0x44 | TAP Opaque |
| 0x45 | TAP VBucket Set |
| 0x46 | TAP Checkout Start |
| 0x47 | TAP Checkpoint End |
As a convention all of the commands ending with "Q" for Quiet. A quiet version of a command will omit responses that are considered uninteresting. Whether a given response is interesting is dependent upon the command. See the descriptions of the set commands (Section 4.2) and set commands (Section 4.3) for examples of commands that include quiet variants.
Possible values of the one-byte field:
| Raw | Description |
|---|---|
| 0x00 | Raw bytes |
All communication is initiated by a request from the client, and the server will respond to each request with zero or multiple packets for each request. If the status code of a response packet is non-nil, the body of the packet will contain a textual error message. If the status code is nil, the command opcode will define the layout of the body of the message.
The following figure illustrates the packet layout for a packet with an error message.
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x81 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x01 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x09 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
24| 0x4e ('N') | 0x6f ('o') | 0x74 ('t') | 0x20 (' ') |
+---------------+---------------+---------------+---------------+
28| 0x66 ('f') | 0x6f ('o') | 0x75 ('u') | 0x6e ('n') |
+---------------+---------------+---------------+---------------+
32| 0x64 ('d') |
+---------------+
Total 33 bytes (24 byte header, and 9 bytes value)
Field (offset) (value)
Magic (0) : 0x81
Opcode (1) : 0x00
Key length (2,3) : 0x0000
Extra length (4) : 0x00
Data type (5) : 0x00
Status (6,7) : 0x0001
Total body (8-11) : 0x00000009
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000000
Extras : None
Key : None
Value (24-32): The textual string "Not found"
Request:
- MUST NOT have extras.
- MUST have key.
- MUST NOT have value.
Response (if found):
- MUST have extras.
- MAY have key.
- MAY have value.
Extra data for the get commands:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| Flags |
+---------------+---------------+---------------+---------------+
Total 4 bytes
The get command gets a single key. The getq command will not send a response on a cache miss. Getk and getkq differs from get and getq by adding the key into the response packet.
Clients should implement multi-get (still important for reducing network roundtrips!) as n pipelined requests, the first n-1 being getq/getkq, the last being a regular get/getk. That way you're guaranteed to get a response, and you know when the server's done. You can also do the naive thing and send n pipelined get/getks, but then you could potentially get back a lot of "NOT_FOUND" error code packets. Alternatively, you can send 'n' getq/getkqs, followed by a 'noop' command.
To request the data associated with the key "Hello" the following fields must be specified in the packet.
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x80 | 0x00 | 0x00 | 0x05 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x05 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
24| 0x48 ('H') | 0x65 ('e') | 0x6c ('l') | 0x6c ('l') |
+---------------+---------------+---------------+---------------+
28| 0x6f ('o') |
+---------------+
Total 29 bytes (24 byte header, and 5 bytes key)
Field (offset) (value)
Magic (0) : 0x80
Opcode (1) : 0x00
Key length (2,3) : 0x0005
Extra length (4) : 0x00
Data type (5) : 0x00
VBucket (6,7) : 0x0000
Total body (8-11) : 0x00000005
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000000
Extras : None
Key (24-29): The textual string: "Hello"
Value : None
If the item exist on the server the following packet is returned, otherwise a packet with status code != 0 will be returned (see Introduction (Section 4.1))
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x81 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
4| 0x04 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x09 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x01 |
+---------------+---------------+---------------+---------------+
24| 0xde | 0xad | 0xbe | 0xef |
+---------------+---------------+---------------+---------------+
28| 0x57 ('W') | 0x6f ('o') | 0x72 ('r') | 0x6c ('l') |
+---------------+---------------+---------------+---------------+
32| 0x64 ('d') |
+---------------+
Total 33 bytes (24 byte header, 4 byte extras and 5 byte value)
Field (offset) (value)
Magic (0) : 0x81
Opcode (1) : 0x00
Key length (2,3) : 0x0000
Extra length (4) : 0x04
Data type (5) : 0x00
Status (6,7) : 0x0000
Total body (8-11) : 0x00000009
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000001
Extras :
Flags (24-27): 0xdeadbeef
Key : None
Value (28-32): The textual string "World"
The response packet for a getk and getkq request differs from get(q) in that the key is present:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x81 | 0x00 | 0x00 | 0x05 |
+---------------+---------------+---------------+---------------+
4| 0x04 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x09 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x01 |
+---------------+---------------+---------------+---------------+
24| 0xde | 0xad | 0xbe | 0xef |
+---------------+---------------+---------------+---------------+
28| 0x48 ('H') | 0x65 ('e') | 0x6c ('l') | 0x6c ('l') |
+---------------+---------------+---------------+---------------+
32| 0x6f ('o') | 0x57 ('W') | 0x6f ('o') | 0x72 ('r') |
+---------------+---------------+---------------+---------------+
36| 0x6c ('l') | 0x64 ('d') |
+---------------+---------------+
Total 38 bytes (24 byte header, 4 byte extras, 5 byte key
and 5 byte value)
Field (offset) (value)
Magic (0) : 0x81
Opcode (1) : 0x00
Key length (2,3) : 0x0005
Extra length (4) : 0x04
Data type (5) : 0x00
Status (6,7) : 0x0000
Total body (8-11) : 0x00000009
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000001
Extras :
Flags (24-27): 0xdeadbeef
Key (28-32): The textual string: "Hello"
Value (33-37): The textual string: "World"
Request:
- MUST have extras.
- MUST have key.
- MAY have value.
Extra data for set/add/replace:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| Flags |
+---------------+---------------+---------------+---------------+
4| Expiration |
+---------------+---------------+---------------+---------------+
Total 8 bytes
Response:
- MUST have CAS
- MUST NOT have extras
- MUST NOT have key
- MUST NOT have value
Constraints:
- If the Data Version Check (CAS) is nonzero, the requested operation MUST only succeed if the item exists and has a CAS value identical to the provided value.
- Add MUST fail if the item already exist.
- Replace MUST fail if the item doesn't exist.
- Set should store the data unconditionally if the item exists or not.
Quiet mutations only return responses on failure. Success is considered the general case and is suppressed when in quiet mode, but errors should not be allowed to go unnoticed.
The following figure shows an add-command for with key = "Hello", value = "World", flags = 0xdeadbeef and expiry: in two hours.
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x80 | 0x02 | 0x00 | 0x05 |
+---------------+---------------+---------------+---------------+
4| 0x08 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x12 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
24| 0xde | 0xad | 0xbe | 0xef |
+---------------+---------------+---------------+---------------+
28| 0x00 | 0x00 | 0x0e | 0x10 |
+---------------+---------------+---------------+---------------+
32| 0x48 ('H') | 0x65 ('e') | 0x6c ('l') | 0x6c ('l') |
+---------------+---------------+---------------+---------------+
36| 0x6f ('o') | 0x57 ('W') | 0x6f ('o') | 0x72 ('r') |
+---------------+---------------+---------------+---------------+
40| 0x6c ('l') | 0x64 ('d') |
+---------------+---------------+
Total 42 bytes (24 byte header, 8 byte extras, 5 byte key and
5 byte value)
Field (offset) (value)
Magic (0) : 0x80
Opcode (1) : 0x02
Key length (2,3) : 0x0005
Extra length (4) : 0x08
Data type (5) : 0x00
VBucket (6,7) : 0x0000
Total body (8-11) : 0x00000012
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000000
Extras :
Flags (24-27): 0xdeadbeef
Expiry (28-31): 0x00000e10
Key (32-36): The textual string "Hello"
Value (37-41): The textual string "World"
The result of the operation is signaled through the status code. If the command succeeds, the CAS value for the item is returned in the CAS-field of the packet:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x81 | 0x02 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x01 |
+---------------+---------------+---------------+---------------+
Total 24 bytes
Field (offset) (value)
Magic (0) : 0x81
Opcode (1) : 0x02
Key length (2,3) : 0x0000
Extra length (4) : 0x00
Data type (5) : 0x00
Status (6,7) : 0x0000
Total body (8-11) : 0x00000000
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000001
Extras : None
Key : None
Value : None
Request:
- MUST NOT have extras.
- MUST have key.
- MUST NOT have value.
Response:
- MUST NOT have extras
- MUST NOT have key
- MUST NOT have value
Delete the item with the specific key. Quiet deletions only return responses on failure. Success is considered the general case and is suppressed when in quiet mode, but errors should not be allowed to go unnoticed.
The following figure shows a delete message for the item "Hello".
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x80 | 0x04 | 0x00 | 0x05 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x05 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
24| 0x48 ('H') | 0x65 ('e') | 0x6c ('l') | 0x6c ('l') |
+---------------+---------------+---------------+---------------+
28| 0x6f ('o') |
+---------------+
Total 29 bytes (24 byte header, 5 byte value)
Field (offset) (value) Magic (0) : 0x80 Opcode (1) : 0x04 Key length (2,3) : 0x0005 Extra length (4) : 0x00 Data type (5) : 0x00 VBucket (6,7) : 0x0000 Total body (8-11) : 0x00000005 Opaque (12-15): 0x00000000 CAS (16-23): 0x0000000000000000 Extras : None Key : The textual string "Hello" Value : None
The result of the operation is signaled through the status code.
Request:
- MUST have extras.
- MUST have key.
- MUST NOT have value.
Extra data for incr/decr:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| Amount to add / subtract |
| |
+---------------+---------------+---------------+---------------+
8| Initial value |
| |
+---------------+---------------+---------------+---------------+
16| Expiration |
+---------------+---------------+---------------+---------------+
Total 20 bytes
Response:
-
MUST NOT have extras.
-
MUST NOT have key.
-
MUST have value.
Byte/ 0 | 1 | 2 | 3 | / | | | | |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7| +---------------+---------------+---------------+---------------+ 0| 64-bit unsigned response. | | | +---------------+---------------+---------------+---------------+ Total 8 bytes
These commands will either add or remove the specified amount to the requested counter. If you want to set the value of the counter with add/set/replace, the objects data must be the ascii representation of the value and not the byte values of a 64 bit integer.
If the counter does not exist, one of two things may happen:
If the expiration value is all one-bits (0xffffffff), the operation will fail with NOT_FOUND. 2. For all other expiration values, the operation will succeed by seeding the value for this key with the provided initial value to expire with the provided expiration time. The flags will be set to zero. Decrementing a counter will never result in a "negative value" (or cause the counter to "wrap"). instead the counter is set to 0. Incrementing the counter may cause the counter to wrap.
Quiet increment / decrement only return responses on failure. Success is considered the general case and is suppressed when in quiet mode, but errors should not be allowed to go unnoticed.
The following figure shows an incr-command for key = "counter", delta = 0x01, initial = 0x00 which expires in two hours.
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x80 | 0x05 | 0x00 | 0x07 |
+---------------+---------------+---------------+---------------+
4| 0x14 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x1b |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
24| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
28| 0x00 | 0x00 | 0x00 | 0x01 |
+---------------+---------------+---------------+---------------+
32| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
36| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
40| 0x00 | 0x00 | 0x0e | 0x10 |
+---------------+---------------+---------------+---------------+
44| 0x63 ('c') | 0x6f ('o') | 0x75 ('u') | 0x6e ('n') |
+---------------+---------------+---------------+---------------+
48| 0x74 ('t') | 0x65 ('e') | 0x72 ('r') |
+---------------+---------------+---------------+
Total 51 bytes (24 byte header, 20 byte extras, 7 byte key)
Field (offset) (value)
Magic (0) : 0x80
Opcode (1) : 0x05
Key length (2,3) : 0x0007
Extra length (4) : 0x14
Data type (5) : 0x00
VBucket (6,7) : 0x0000
Total body (8-11) : 0x0000001b
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000000
Extras :
Delta (24-31): 0x0000000000000001
Initial (32-39): 0x0000000000000000
Expiration (40-43): 0x00000e10
Key : Textual string "counter"
Value : None
If the key doesn't exist, the server will respond with the initial value. If not the incremented value will be returned. Let's assume that the key didn't exist, so the initial value is returned:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x81 | 0x05 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x08 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x05 |
+---------------+---------------+---------------+---------------+
24| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
28| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
Total 32 bytes (24 byte header, 8 byte value)
Field (offset) (value)
Magic (0) : 0x81
Opcode (1) : 0x05
Key length (2,3) : 0x0000
Extra length (4) : 0x00
Data type (5) : 0x00
Status (6,7) : 0x0000
Total body (8-11) : 0x00000008
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000005
Extras : None
Key : None
Value : 0x0000000000000000
Request:
- MUST NOT have extras.
- MUST NOT have key.
- MUST NOT have value.
Response:
- MUST NOT have extras.
- MUST NOT have key.
- MUST NOT have value.
Close the connection to the server. Quiet quit should not receive a response packet.
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x80 | 0x07 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
Total 24 bytes
Field (offset) (value) Magic (0) : 0x80 Opcode (1) : 0x07 Key length (2,3) : 0x0000 Extra length (4) : 0x00 Data type (5) : 0x00 VBucket (6,7) : 0x0000 Total body (8-11) : 0x00000000 Opaque (12-15): 0x00000000 CAS (16-23): 0x0000000000000000 Extras : None Key : None Value : None
The response-packet contains no extra data, and the result of the operation is signaled through the status code. The server will then close the connection.
Request:
- MAY have extras.
- MUST NOT have key.
- MUST NOT have value.
Extra data for flush:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| Expiration |
+---------------+---------------+---------------+---------------+
Total 4 bytes
Response:
- MUST NOT have extras.
- MUST NOT have key.
- MUST NOT have value.
Flush the items in the cache now or some time in the future as specified by the expiration field. Quiet flush only return responses on failure. Success is considered the general case and is suppressed when in quiet mode, but errors should not be allowed to go unnoticed.
Note: Is it not recommended that you flush a bucket directly with Couchbase Server (Especially with Couchbase Buckets). Instead you should instigate a flush using the Cluster Manager's REST API.
To flush the cache (delete all items) in two hours, the set the following values in the request
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x80 | 0x08 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
4| 0x04 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x04 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
24| 0x00 | 0x00 | 0x0e | 0x10 |
+---------------+---------------+---------------+---------------+
Total 28 bytes (24 byte header, 4 byte body)
Field (offset) (value)
Magic (0) : 0x80
Opcode (1) : 0x08
Key length (2,3) : 0x0000
Extra length (4) : 0x04
Data type (5) : 0x00
VBucket (6,7) : 0x0000
Total body (8-11) : 0x00000004
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000000
Extras :
Expiry (24-27): 0x000e10
Key : None
Value : None
The result of the operation is signaled through the status code.
Request:
- MUST NOT have extras.
- MUST NOT have key.
- MUST NOT have value.
Response:
- MUST NOT have extras.
- MUST NOT have key.
- MUST NOT have value.
Used as a keep alive.
####Example
Noop request:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x80 | 0x0a | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
Total 24 bytes
Field (offset) (value)
Magic (0) : 0x80
Opcode (1) : 0x0a
Key length (2,3) : 0x0000
Extra length (4) : 0x00
Data type (5) : 0x00
VBucket (6,7) : 0x0000
Total body (8-11) : 0x00000000
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000000
Extras : None
Key : None
Value : None
The result of the operation is signaled through the status code.
Request:
- MUST NOT have extras.
- MUST NOT have key.
- MUST NOT have value.
Response:
- MUST NOT have extras.
- MUST NOT have key.
- MUST have value.
Request the server version.
The server responds with a packet containing the version string in the body with the following format: "x.y.z"
Request:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x80 | 0x0b | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
Total 24 bytes
Field (offset) (value)
Magic (0) : 0x80
Opcode (1) : 0x0b
Key length (2,3) : 0x0000
Extra length (4) : 0x00
Data type (5) : 0x00
VBucket (6,7) : 0x0000
Total body (8-11) : 0x00000000
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000000
Extras : None
Response:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x81 | 0x0b | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x05 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
24| 0x31 ('1') | 0x2e ('.') | 0x33 ('3') | 0x2e ('.') |
+---------------+---------------+---------------+---------------+
28| 0x31 ('1') |
+---------------+
Total 29 bytes (24 byte header, 5 byte body)
Field (offset) (value)
Magic (0) : 0x81
Opcode (1) : 0x0b
Key length (2,3) : 0x0000
Extra length (4) : 0x00
Data type (5) : 0x00
Status (6,7) : 0x0000
Total body (8-11) : 0x00000005
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000000
Extras : None
Key : None
Value : Textual string "1.3.1"
Request:
- MUST NOT have extras.
- MUST have key.
- MUST have value.
Response:
- MUST NOT have extras.
- MUST NOT have key.
- MUST NOT have value.
- MUST have CAS
These commands will either append or prepend the specified value to the requested key.
The following example appends '!' to the 'Hello' key.
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x80 | 0x0e | 0x00 | 0x05 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x06 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
24| 0x48 ('H') | 0x65 ('e') | 0x6c ('l') | 0x6c ('l') |
+---------------+---------------+---------------+---------------+
28| 0x6f ('o') | 0x21 ('!') |
+---------------+---------------+
Total 30 bytes (24 byte header, 5 byte key, 1 byte value)
Field (offset) (value)
Magic (0) : 0x80
Opcode (1) : 0x0e
Key length (2,3) : 0x0005
Extra length (4) : 0x00
Data type (5) : 0x00
VBucket (6,7) : 0x0000
Total body (8-11) : 0x00000006
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000000
Extras : None
Key (24-28): The textual string "Hello"
Value (29) : "!"
The result of the operation is signaled through the status code.
Request:
- MUST NOT have extras.
- MAY have key.
- MUST NOT have value.
Response:
- MUST NOT have extras.
- MAY have key.
- MAY have value.
Request server statistics. Without a key specified the server will respond with a "default" set of statistics information. Each piece of statistical information is returned in its own packet (key contains the name of the statistical item and the body contains the value in ASCII format). The sequence of return packets is terminated with a packet that contains no key and no value.
The following example requests all statistics from the server
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x80 | 0x10 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
Total 24 bytes
Field (offset) (value)
Magic (0) : 0x80
Opcode (1) : 0x10
Key length (2,3) : 0x0000
Extra length (4) : 0x00
Data type (5) : 0x00
VBucket (6,7) : 0x0000
Total body (8-11) : 0x00000000
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000000
Extras : None
Key : None
Value : None
The server will send each value in a separate packet with an "empty" packet no key / no value) to terminate the sequence. Each of the response packets look like the following example:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| 0x81 | 0x10 | 0x00 | 0x03 |
+---------------+---------------+---------------+---------------+
4| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
8| 0x00 | 0x00 | 0x00 | 0x07 |
+---------------+---------------+---------------+---------------+
12| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
16| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
20| 0x00 | 0x00 | 0x00 | 0x00 |
+---------------+---------------+---------------+---------------+
24| 0x70 ('p') | 0x69 ('i') | 0x64 ('d') | 0x33 ('3') |
+---------------+---------------+---------------+---------------+
28| 0x30 ('0') | 0x37 ('7') | 0x38 ('8') |
+---------------+---------------+---------------+
Total 31 bytes (24 byte header, 3 byte key, 4 byte body)
Field (offset) (value)
Magic (0) : 0x81
Opcode (1) : 0x10
Key length (2,3) : 0x0003
Extra length (4) : 0x00
Data type (5) : 0x00
Status (6,7) : 0x0000
Total body (8-11) : 0x00000007
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000000
Exstras : None
Key : The textual string "pid"
Value : The textual string "3078"
Request:
- MUST have extras.
- MUST NOT have key.
- MUST NOT have value.
Extra data for flush:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| Verbosity |
+---------------+---------------+---------------+---------------+
Total 4 bytes
Response:
- MUST NOT have extras.
- MUST NOT have key.
- MUST NOT have value.
Set the verbosity level of the server. This may cause your memcached server to generate more or less output.
To set the verbosity level to two, set the following values in the request
TODO: add me
The result of the operation is signaled through the status code.
Request:
- MUST have extras.
- MUST have key.
- MUST NOT have value.
Extra data for touch/gat:
Byte/ 0 | 1 | 2 | 3 |
/ | | | |
|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
+---------------+---------------+---------------+---------------+
0| Expiration |
+---------------+---------------+---------------+---------------+
Total 4 bytes
Touch is used to set a new expiration time for an existing item. GAT (Get and touch) and GATQ will return the value for the object if it is present in the cache.
Example TODO: add me
TODO: add me
TODO: add me
TODO: add me
TODO: add me
TODO: add me
TODO: add me