Merge branch 'cassandra-1.2' into cassandra-2.0
Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/3bd65965 Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/3bd65965 Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/3bd65965 Branch: refs/heads/cassandra-2.0 Commit: 3bd65965fd4049614676b6b13ca349401d4e034e Parents: 22d8744 1b4c9b4 Author: Jason Brown <jasedbr...@gmail.com> Authored: Tue Dec 17 11:04:03 2013 -0800 Committer: Jason Brown <jasedbr...@gmail.com> Committed: Tue Dec 17 11:04:03 2013 -0800 ---------------------------------------------------------------------- doc/native_protocol_v1.spec | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/cassandra/blob/3bd65965/doc/native_protocol_v1.spec ---------------------------------------------------------------------- diff --cc doc/native_protocol_v1.spec index 0d2ff05,0000000..08cb91e mode 100644,000000..100644 --- a/doc/native_protocol_v1.spec +++ b/doc/native_protocol_v1.spec @@@ -1,636 -1,0 +1,636 @@@ + + CQL BINARY PROTOCOL v1 + + +Table of Contents + + 1. Overview + 2. Frame header + 2.1. version + 2.2. flags + 2.3. stream + 2.4. opcode + 2.5. length + 3. Notations + 4. Messages + 4.1. Requests + 4.1.1. STARTUP + 4.1.2. CREDENTIALS + 4.1.3. OPTIONS + 4.1.4. QUERY + 4.1.5. PREPARE + 4.1.6. EXECUTE + 4.1.7. REGISTER + 4.2. Responses + 4.2.1. ERROR + 4.2.2. READY + 4.2.3. AUTHENTICATE + 4.2.4. SUPPORTED + 4.2.5. RESULT + 4.2.5.1. Void + 4.2.5.2. Rows + 4.2.5.3. Set_keyspace + 4.2.5.4. Prepared + 4.2.5.5. Schema_change + 4.2.6. EVENT + 5. Compression + 6. Collection types + 7. Error codes + + +1. Overview + + The CQL binary protocol is a frame based protocol. Frames are defined as: + + 0 8 16 24 32 + +---------+---------+---------+---------+ + | version | flags | stream | opcode | + +---------+---------+---------+---------+ + | length | + +---------+---------+---------+---------+ + | | + . ... body ... . + . . + . . + +---------------------------------------- + + The protocol is big-endian (network byte order). + + Each frame contains a fixed size header (8 bytes) followed by a variable size + body. The header is described in Section 2. The content of the body depends + on the header opcode value (the body can in particular be empty for some + opcode values). The list of allowed opcode is defined Section 2.3 and the + details of each corresponding message is described Section 4. + + The protocol distinguishes 2 types of frames: requests and responses. Requests + are those frame sent by the clients to the server, response are the ones sent + by the server. Note however that while communication are initiated by the + client with the server responding to request, the protocol may likely add + server pushes in the future, so responses does not obligatory come right after + a client request. + + Note to client implementors: clients library should always assume that the + body of a given frame may contain more data than what is described in this + document. It will however always be safe to ignore the remaining of the frame + body in such cases. The reason is that this may allow to sometimes extend the + protocol with optional features without needing to change the protocol + version. + + +2. Frame header + +2.1. version + + The version is a single byte that indicate both the direction of the message + (request or response) and the version of the protocol in use. The up-most bit + of version is used to define the direction of the message: 0 indicates a + request, 1 indicates a responses. This can be useful for protocol analyzers to + distinguish the nature of the packet from the direction which it is moving. + The rest of that byte is the protocol version (1 for the protocol defined in + this document). In other words, for this version of the protocol, version will + have one of: + 0x01 Request frame for this protocol version + 0x81 Response frame for this protocol version + + +2.2. flags + + Flags applying to this frame. The flags have the following meaning (described + by the mask that allow to select them): + 0x01: Compression flag. If set, the frame body is compressed. The actual + compression to use should have been set up beforehand through the + Startup message (which thus cannot be compressed; Section 4.1.1). + 0x02: Tracing flag. For a request frame, this indicate the client requires + tracing of the request. Note that not all requests support tracing. + Currently, only QUERY, PREPARE and EXECUTE queries support tracing. + Other requests will simply ignore the tracing flag if set. If a + request support tracing and the tracing flag was set, the response to + this request will have the tracing flag set and contain tracing + information. + If a response frame has the tracing flag set, its body contains + a tracing ID. The tracing ID is a [uuid] and is the first thing in + the frame body. The rest of the body will then be the usual body + corresponding to the response opcode. + + The rest of the flags is currently unused and ignored. + +2.3. stream + + A frame has a stream id (one signed byte). When sending request messages, this + stream id must be set by the client to a positive byte (negative stream id + are reserved for streams initiated by the server; currently all EVENT messages + (section 4.2.6) have a streamId of -1). If a client sends a request message + with the stream id X, it is guaranteed that the stream id of the response to + that message will be X. + + This allow to deal with the asynchronous nature of the protocol. If a client + sends multiple messages simultaneously (without waiting for responses), there + is no guarantee on the order of the responses. For instance, if the client + writes REQ_1, REQ_2, REQ_3 on the wire (in that order), the server might + respond to REQ_3 (or REQ_2) first. Assigning different stream id to these 3 + requests allows the client to distinguish to which request an received answer + respond to. As there can only be 128 different simultaneous stream, it is up + to the client to reuse stream id. + + Note that clients are free to use the protocol synchronously (i.e. wait for + the response to REQ_N before sending REQ_N+1). In that case, the stream id + can be safely set to 0. Clients should also feel free to use only a subset of + the 128 maximum possible stream ids if it is simpler for those + implementation. + +2.4. opcode + + An integer byte that distinguish the actual message: + 0x00 ERROR + 0x01 STARTUP + 0x02 READY + 0x03 AUTHENTICATE + 0x04 CREDENTIALS + 0x05 OPTIONS + 0x06 SUPPORTED + 0x07 QUERY + 0x08 RESULT + 0x09 PREPARE + 0x0A EXECUTE + 0x0B REGISTER + 0x0C EVENT + + Messages are described in Section 4. + + +2.5. length + + A 4 byte integer representing the length of the body of the frame (note: + currently a frame is limited to 256MB in length). + + +3. Notations + + To describe the layout of the frame body for the messages in Section 4, we + define the following: + + [int] A 4 bytes integer + [short] A 2 bytes unsigned integer + [string] A [short] n, followed by n bytes representing an UTF-8 + string. + [long string] An [int] n, followed by n bytes representing an UTF-8 string. + [uuid] A 16 bytes long uuid. + [string list] A [short] n, followed by n [string]. + [bytes] A [int] n, followed by n bytes if n >= 0. If n < 0, + no byte should follow and the value represented is `null`. + [short bytes] A [short] n, followed by n bytes if n >= 0. + + [option] A pair of <id><value> where <id> is a [short] representing + the option id and <value> depends on that option (and can be + of size 0). The supported id (and the corresponding <value>) + will be described when this is used. + [option list] A [short] n, followed by n [option]. + [inet] An address (ip and port) to a node. It consists of one + [byte] n, that represents the address size, followed by n + [byte] representing the IP address (in practice n can only be + either 4 (IPv4) or 16 (IPv6)), following by one [int] + representing the port. + [consistency] A consistency level specification. This is a [short] + representing a consistency level with the following + correspondance: + 0x0000 ANY + 0x0001 ONE + 0x0002 TWO + 0x0003 THREE + 0x0004 QUORUM + 0x0005 ALL + 0x0006 LOCAL_QUORUM + 0x0007 EACH_QUORUM - 0x0010 LOCAL_ONE ++ 0x000A LOCAL_ONE + + [string map] A [short] n, followed by n pair <k><v> where <k> and <v> + are [string]. + [string multimap] A [short] n, followed by n pair <k><v> where <k> is a + [string] and <v> is a [string list]. + + +4. Messages + +4.1. Requests + + Note that outside of their normal responses (described below), all requests + can get an ERROR message (Section 4.2.1) as response. + +4.1.1. STARTUP + + Initialize the connection. The server will respond by either a READY message + (in which case the connection is ready for queries) or an AUTHENTICATE message + (in which case credentials will need to be provided using CREDENTIALS). + + This must be the first message of the connection, except for OPTIONS that can + be sent before to find out the options supported by the server. Once the + connection has been initialized, a client should not send any more STARTUP + message. + + The body is a [string map] of options. Possible options are: + - "CQL_VERSION": the version of CQL to use. This option is mandatory and + currenty, the only version supported is "3.0.0". Note that this is + different from the protocol version. + - "COMPRESSION": the compression algorithm to use for frames (See section 5). + This is optional, if not specified no compression will be used. + + +4.1.2. CREDENTIALS + + Provides credentials information for the purpose of identification. This + message comes as a response to an AUTHENTICATE message from the server, but + can be use later in the communication to change the authentication + information. + + The body is a list of key/value informations. It is a [short] n, followed by n + pair of [string]. These key/value pairs are passed as is to the Cassandra + IAuthenticator and thus the detail of which informations is needed depends on + that authenticator. + + The response to a CREDENTIALS is a READY message (or an ERROR message). + + +4.1.3. OPTIONS + + Asks the server to return what STARTUP options are supported. The body of an + OPTIONS message should be empty and the server will respond with a SUPPORTED + message. + + +4.1.4. QUERY + + Performs a CQL query. The body of the message consists of a CQL query as a [long + string] followed by the [consistency] for the operation. + + Note that the consistency is ignored by some queries (USE, CREATE, ALTER, + TRUNCATE, ...). + + The server will respond to a QUERY message with a RESULT message, the content + of which depends on the query. + + +4.1.5. PREPARE + + Prepare a query for later execution (through EXECUTE). The body consists of + the CQL query to prepare as a [long string]. + + The server will respond with a RESULT message with a `prepared` kind (0x0004, + see Section 4.2.5). + + +4.1.6. EXECUTE + + Executes a prepared query. The body of the message must be: + <id><n><value_1>....<value_n><consistency> + where: + - <id> is the prepared query ID. It's the [short bytes] returned as a + response to a PREPARE message. + - <n> is a [short] indicating the number of following values. + - <value_1>...<value_n> are the [bytes] to use for bound variables in the + prepared query. + - <consistency> is the [consistency] level for the operation. + + Note that the consistency is ignored by some (prepared) queries (USE, CREATE, + ALTER, TRUNCATE, ...). + + The response from the server will be a RESULT message. + + +4.1.7. REGISTER + + Register this connection to receive some type of events. The body of the + message is a [string list] representing the event types to register to. See + section 4.2.6 for the list of valid event types. + + The response to a REGISTER message will be a READY message. + + Please note that if a client driver maintains multiple connections to a + Cassandra node and/or connections to multiple nodes, it is advised to + dedicate a handful of connections to receive events, but to *not* register + for events on all connections, as this would only result in receiving + multiple times the same event messages, wasting bandwidth. + + +4.2. Responses + + This section describes the content of the frame body for the different + responses. Please note that to make room for future evolution, clients should + support extra informations (that they should simply discard) to the one + described in this document at the end of the frame body. + +4.2.1. ERROR + + Indicates an error processing a request. The body of the message will be an + error code ([int]) followed by a [string] error message. Then, depending on + the exception, more content may follow. The error codes are defined in + Section 7, along with their additional content if any. + + +4.2.2. READY + + Indicates that the server is ready to process queries. This message will be + sent by the server either after a STARTUP message if no authentication is + required, or after a successful CREDENTIALS message. + + The body of a READY message is empty. + + +4.2.3. AUTHENTICATE + + Indicates that the server require authentication. This will be sent following + a STARTUP message and must be answered by a CREDENTIALS message from the + client to provide authentication informations. + + The body consists of a single [string] indicating the full class name of the + IAuthenticator in use. + + +4.2.4. SUPPORTED + + Indicates which startup options are supported by the server. This message + comes as a response to an OPTIONS message. + + The body of a SUPPORTED message is a [string multimap]. This multimap gives + for each of the supported STARTUP options, the list of supported values. + + +4.2.5. RESULT + + The result to a query (QUERY, PREPARE or EXECUTE messages). + + The first element of the body of a RESULT message is an [int] representing the + `kind` of result. The rest of the body depends on the kind. The kind can be + one of: + 0x0001 Void: for results carrying no information. + 0x0002 Rows: for results to select queries, returning a set of rows. + 0x0003 Set_keyspace: the result to a `use` query. + 0x0004 Prepared: result to a PREPARE message. + 0x0005 Schema_change: the result to a schema altering query. + + The body for each kind (after the [int] kind) is defined below. + + +4.2.5.1. Void + + The rest of the body for a Void result is empty. It indicates that a query was + successful without providing more information. + + +4.2.5.2. Rows + + Indicates a set of rows. The rest of body of a Rows result is: + <metadata><rows_count><rows_content> + where: + - <metadata> is composed of: + <flags><columns_count><global_table_spec>?<col_spec_1>...<col_spec_n> + where: + - <flags> is an [int]. The bits of <flags> provides information on the + formatting of the remaining informations. A flag is set if the bit + corresponding to its `mask` is set. Supported flags are, given there + mask: + 0x0001 Global_tables_spec: if set, only one table spec (keyspace + and table name) is provided as <global_table_spec>. If not + set, <global_table_spec> is not present. + - <columns_count> is an [int] representing the number of columns selected + by the query this result is of. It defines the number of <col_spec_i> + elements in and the number of element for each row in <rows_content>. + - <global_table_spec> is present if the Global_tables_spec is set in + <flags>. If present, it is composed of two [string] representing the + (unique) keyspace name and table name the columns return are of. + - <col_spec_i> specifies the columns returned in the query. There is + <column_count> such column specification that are composed of: + (<ksname><tablename>)?<column_name><type> + The initial <ksname> and <tablename> are two [string] are only present + if the Global_tables_spec flag is not set. The <column_name> is a + [string] and <type> is an [option] that correspond to the column name + and type. The option for <type> is either a native type (see below), + in which case the option has no value, or a 'custom' type, in which + case the value is a [string] representing the full qualified class + name of the type represented. Valid option ids are: + 0x0000 Custom: the value is a [string], see above. + 0x0001 Ascii + 0x0002 Bigint + 0x0003 Blob + 0x0004 Boolean + 0x0005 Counter + 0x0006 Decimal + 0x0007 Double + 0x0008 Float + 0x0009 Int + 0x000A Text + 0x000B Timestamp + 0x000C Uuid + 0x000D Varchar + 0x000E Varint + 0x000F Timeuuid + 0x0010 Inet + 0x0020 List: the value is an [option], representing the type + of the elements of the list. + 0x0021 Map: the value is two [option], representing the types of the + keys and values of the map + 0x0022 Set: the value is an [option], representing the type + of the elements of the set + - <rows_count> is an [int] representing the number of rows present in this + result. Those rows are serialized in the <rows_content> part. + - <rows_content> is composed of <row_1>...<row_m> where m is <rows_count>. + Each <row_i> is composed of <value_1>...<value_n> where n is + <columns_count> and where <value_j> is a [bytes] representing the value + returned for the jth column of the ith row. In other words, <rows_content> + is composed of (<rows_count> * <columns_count>) [bytes]. + + +4.2.5.3. Set_keyspace + + The result to a `use` query. The body (after the kind [int]) is a single + [string] indicating the name of the keyspace that has been set. + + +4.2.5.4. Prepared + + The result to a PREPARE message. The rest of the body of a Prepared result is: + <id><metadata> + where: + - <id> is [short bytes] representing the prepared query ID. + - <metadata> is defined exactly as for a Rows RESULT (See section 4.2.5.2). + + Note that prepared query ID return is global to the node on which the query + has been prepared. It can be used on any connection to that node and this + until the node is restarted (after which the query must be reprepared). + +4.2.5.5. Schema_change + + The result to a schema altering query (creation/update/drop of a + keyspace/table/index). The body (after the kind [int]) is composed of 3 + [string]: + <change><keyspace><table> + where: + - <change> describe the type of change that has occured. It can be one of + "CREATED", "UPDATED" or "DROPPED". + - <keyspace> is the name of the affected keyspace or the keyspace of the + affected table. + - <table> is the name of the affected table. <table> will be empty (i.e. + the empty string "") if the change was affecting a keyspace and not a + table. + + Note that queries to create and drop an index are considered as change + updating the table the index is on. + + +4.2.6. EVENT + + And event pushed by the server. A client will only receive events for the + type it has REGISTER to. The body of an EVENT message will start by a + [string] representing the event type. The rest of the message depends on the + event type. The valid event types are: + - "TOPOLOGY_CHANGE": events related to change in the cluster topology. + Currently, events are sent when new nodes are added to the cluster, and + when nodes are removed. The body of the message (after the event type) + consists of a [string] and an [inet], corresponding respectively to the + type of change ("NEW_NODE" or "REMOVED_NODE") followed by the address of + the new/removed node. + - "STATUS_CHANGE": events related to change of node status. Currently, + up/down events are sent. The body of the message (after the event type) + consists of a [string] and an [inet], corresponding respectively to the + type of status change ("UP" or "DOWN") followed by the address of the + concerned node. + - "SCHEMA_CHANGE": events related to schema change. The body of the message + (after the event type) consists of 3 [string] corresponding respectively + to the type of schema change ("CREATED", "UPDATED" or "DROPPED"), + followed by the name of the affected keyspace and the name of the + affected table within that keyspace. For changes that affect a keyspace + directly, the table name will be empty (i.e. the empty string ""). + + All EVENT message have a streamId of -1 (Section 2.3). + + Please note that "NEW_NODE" and "UP" events are sent based on internal Gossip + communication and as such may be sent a short delay before the binary + protocol server on the newly up node is fully started. Clients are thus + advise to wait a short time before trying to connect to the node (1 seconds + should be enough), otherwise they may experience a connection refusal at + first. + + +5. Compression + + Frame compression is supported by the protocol, but then only the frame body + is compressed (the frame header should never be compressed). + + Before being used, client and server must agree on a compression algorithm to + use, which is done in the STARTUP message. As a consequence, a STARTUP message + must never be compressed. However, once the STARTUP frame has been received + by the server can be compressed (including the response to the STARTUP + request). Frame do not have to be compressed however, even if compression has + been agreed upon (a server may only compress frame above a certain size at its + discretion). A frame body should be compressed if and only if the compressed + flag (see Section 2.2) is set. + + +6. Collection types + + This section describe the serialization format for the collection types: + list, map and set. This serialization format is both useful to decode values + returned in RESULT messages but also to encode values for EXECUTE ones. + + The serialization formats are: + List: a [short] n indicating the size of the list, followed by n elements. + Each element is [short bytes] representing the serialized element + value. + Map: a [short] n indicating the size of the map, followed by n entries. + Each entry is composed of two [short bytes] representing the key and + the value of the entry map. + Set: a [short] n indicating the size of the set, followed by n elements. + Each element is [short bytes] representing the serialized element + value. + + +7. Error codes + + The supported error codes are described below: + 0x0000 Server error: something unexpected happened. This indicates a + server-side bug. + 0x000A Protocol error: some client message triggered a protocol + violation (for instance a QUERY message is sent before a STARTUP + one has been sent) + 0x0100 Bad credentials: CREDENTIALS request failed because Cassandra + did not accept the provided credentials. + + 0x1000 Unavailable exception. The rest of the ERROR message body will be + <cl><required><alive> + where: + <cl> is the [consistency] level of the query having triggered + the exception. + <required> is an [int] representing the number of node that + should be alive to respect <cl> + <alive> is an [int] representing the number of replica that + were known to be alive when the request has been + processed (since an unavailable exception has been + triggered, there will be <alive> < <required>) + 0x1001 Overloaded: the request cannot be processed because the + coordinator node is overloaded + 0x1002 Is_bootstrapping: the request was a read request but the + coordinator node is bootstrapping + 0x1003 Truncate_error: error during a truncation error. + 0x1100 Write_timeout: Timeout exception during a write request. The rest + of the ERROR message body will be + <cl><received><blockfor><writeType> + where: + <cl> is the [consistency] level of the query having triggered + the exception. + <received> is an [int] representing the number of nodes having + acknowledged the request. + <blockfor> is the number of replica whose acknowledgement is + required to achieve <cl>. + <writeType> is a [string] that describe the type of the write + that timeouted. The value of that string can be one + of: + - "SIMPLE": the write was a non-batched + non-counter write. + - "BATCH": the write was a (logged) batch write. + If this type is received, it means the batch log + has been successfully written (otherwise a + "BATCH_LOG" type would have been send instead). + - "UNLOGGED_BATCH": the write was an unlogged + batch. Not batch log write has been attempted. + - "COUNTER": the write was a counter write + (batched or not). + - "BATCH_LOG": the timeout occured during the + write to the batch log when a (logged) batch + write was requested. + 0x1200 Read_timeout: Timeout exception during a read request. The rest + of the ERROR message body will be + <cl><received><blockfor><data_present> + where: + <cl> is the [consistency] level of the query having triggered + the exception. + <received> is an [int] representing the number of nodes having + answered the request. + <blockfor> is the number of replica whose response is + required to achieve <cl>. Please note that it is + possible to have <received> >= <blockfor> if + <data_present> is false. And also in the (unlikely) + case were <cl> is achieved but the coordinator node + timeout while waiting for read-repair + acknowledgement. + <data_present> is a single byte. If its value is 0, it means + the replica that was asked for data has not + responded. Otherwise, the value is != 0. + + 0x2000 Syntax_error: The submitted query has a syntax error. + 0x2100 Unauthorized: The logged user doesn't have the right to perform + the query. + 0x2200 Invalid: The query is syntactically correct but invalid. + 0x2300 Config_error: The query is invalid because of some configuration issue + 0x2400 Already_exists: The query attempted to create a keyspace or a + table that was already existing. The rest of the ERROR message + body will be <ks><table> where: + <ks> is a [string] representing either the keyspace that + already exists, or the keyspace in which the table that + already exists is. + <table> is a [string] representing the name of the table that + already exists. If the query was attempting to create a + keyspace, <table> will be present but will be the empty + string. + 0x2500 Unprepared: Can be thrown while a prepared statement tries to be + executed if the provide prepared statement ID is not known by + this host. The rest of the ERROR message body will be [short + bytes] representing the unknown ID.