From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp36.i.mail.ru (smtp36.i.mail.ru [94.100.177.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id 0C55F42EF67 for ; Tue, 30 Jun 2020 02:15:53 +0300 (MSK) From: Vladislav Shpilevoy Date: Tue, 30 Jun 2020 01:15:24 +0200 Message-Id: <3153acf5a8f5e34411a44069e8681357abc4b3a7.1593472477.git.v.shpilevoy@tarantool.org> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [Tarantool-patches] [PATCH v2 05/19] xrow: introduce CONFIRM and ROLLBACK entries List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: tarantool-patches@dev.tarantool.org, sergepetrenko@tarantool.org From: Serge Petrenko Add methods to encode/decode CONFIRM entry. A CONFIRM entry will be written to WAL by synchronous replication master as soon as it finds that the transaction was applied on a quorum of replicas. CONFIRM rows share the same header with other rows in WAL, but their body differs: it's just a map containing replica_id and lsn of the last confirmed transaction. ROLLBACK request contains the same data as CONFIRM request. The only difference is the request semantics. While a CONFIRM request releases all the limbo entries up to the given lsn, the ROLLBACK request rolls back all the entries with lsn greater than given one. Part-of #4847 Part-of #4848 @TarantoolBot document Title: document synchronous replication auxiliary requests Two new iproto request codes are added: * IPROTO_CONFIRM = 0x28 (decimal 40) * IPROTO_ROLLBACK = 0x29 (decimal 41) Both entries share the same request body (it's a map of 2 items): IPROTO_REPLICA_ID : leader_id - id of the synchronous replication leader, IPROTO_LSN : leader_lsn - lsn of the last confirmed transaction. The CONFIRM and ROLLBACK ops are written to WAL, so their header also has IPROTO_REPLICA_ID and IPROTO_LSN fields, which are replica_id : lsn of the instance that wrote these records. leader_id may be different from replica_id, and leader_lsn refers to some past moment in time. When an instance either reads from WAL or receives a CONFIRM entry via replication, it knows that all the leader's synchronous transactions up to the given leader_lsn may be safely committed. When an instance receives or reads a ROLLBACK entry, it knows that all the leader's transactions received up to the given point in time must be rolled back, starting with a transaction, which begins with leader_lsn + 1. --- src/box/iproto_constants.h | 12 +++++ src/box/xrow.c | 106 +++++++++++++++++++++++++++++++++++++ src/box/xrow.h | 46 ++++++++++++++++ 3 files changed, 164 insertions(+) diff --git a/src/box/iproto_constants.h b/src/box/iproto_constants.h index e38ee4529..6b850f101 100644 --- a/src/box/iproto_constants.h +++ b/src/box/iproto_constants.h @@ -219,6 +219,11 @@ enum iproto_type { /** The maximum typecode used for box.stat() */ IPROTO_TYPE_STAT_MAX, + /** A confirmation message for synchronous transactions. */ + IPROTO_CONFIRM = 40, + /** A rollback message for synchronous transactions. */ + IPROTO_ROLLBACK = 41, + /** PING request */ IPROTO_PING = 64, /** Replication JOIN command */ @@ -316,6 +321,13 @@ dml_request_key_map(uint32_t type) return iproto_body_key_map[type]; } +/** CONFIRM/ROLLBACK entries for synchronous replication. */ +static inline bool +iproto_type_is_synchro_request(uint32_t type) +{ + return type == IPROTO_CONFIRM || type == IPROTO_ROLLBACK; +} + /** This is an error. */ static inline bool iproto_type_is_error(uint32_t type) diff --git a/src/box/xrow.c b/src/box/xrow.c index bb64864b2..39d1814c4 100644 --- a/src/box/xrow.c +++ b/src/box/xrow.c @@ -878,6 +878,112 @@ xrow_encode_dml(const struct request *request, struct region *region, return iovcnt; } +static int +xrow_encode_confirm_rollback(struct xrow_header *row, uint32_t replica_id, + int64_t lsn, int type) +{ + size_t len = mp_sizeof_map(2) + mp_sizeof_uint(IPROTO_REPLICA_ID) + + mp_sizeof_uint(replica_id) + mp_sizeof_uint(IPROTO_LSN) + + mp_sizeof_uint(lsn); + char *buf = (char *)region_alloc(&fiber()->gc, len); + if (buf == NULL) { + diag_set(OutOfMemory, len, "region_alloc", "buf"); + return -1; + } + char *pos = buf; + + pos = mp_encode_map(pos, 2); + pos = mp_encode_uint(pos, IPROTO_REPLICA_ID); + pos = mp_encode_uint(pos, replica_id); + pos = mp_encode_uint(pos, IPROTO_LSN); + pos = mp_encode_uint(pos, lsn); + + memset(row, 0, sizeof(*row)); + + row->body[0].iov_base = buf; + row->body[0].iov_len = len; + row->bodycnt = 1; + + row->type = type; + + return 0; +} + +int +xrow_encode_confirm(struct xrow_header *row, uint32_t replica_id, int64_t lsn) +{ + return xrow_encode_confirm_rollback(row, replica_id, lsn, + IPROTO_CONFIRM); +} + +int +xrow_encode_rollback(struct xrow_header *row, uint32_t replica_id, int64_t lsn) +{ + return xrow_encode_confirm_rollback(row, replica_id, lsn, + IPROTO_ROLLBACK); +} + +static int +xrow_decode_confirm_rollback(struct xrow_header *row, uint32_t *replica_id, + int64_t *lsn) +{ + if (row->bodycnt == 0) { + diag_set(ClientError, ER_INVALID_MSGPACK, "request body"); + return -1; + } + + assert(row->bodycnt == 1); + + const char * const data = (const char *)row->body[0].iov_base; + const char * const end = data + row->body[0].iov_len; + const char *d = data; + if (mp_check(&d, end) != 0 || mp_typeof(*data) != MP_MAP) { + xrow_on_decode_err(data, end, ER_INVALID_MSGPACK, + "request body"); + return -1; + } + + d = data; + uint32_t map_size = mp_decode_map(&d); + for (uint32_t i = 0; i < map_size; i++) { + enum mp_type type = mp_typeof(*d); + if (type != MP_UINT) { + mp_next(&d); + mp_next(&d); + continue; + } + uint8_t key = mp_decode_uint(&d); + if (key >= IPROTO_KEY_MAX || iproto_key_type[key] != type) { + xrow_on_decode_err(data, end, ER_INVALID_MSGPACK, + "request body"); + return -1; + } + switch (key) { + case IPROTO_REPLICA_ID: + *replica_id = mp_decode_uint(&d); + break; + case IPROTO_LSN: + *lsn = mp_decode_uint(&d); + break; + default: + mp_next(&d); + } + } + return 0; +} + +int +xrow_decode_confirm(struct xrow_header *row, uint32_t *replica_id, int64_t *lsn) +{ + return xrow_decode_confirm_rollback(row, replica_id, lsn); +} + +int +xrow_decode_rollback(struct xrow_header *row, uint32_t *replica_id, int64_t *lsn) +{ + return xrow_decode_confirm_rollback(row, replica_id, lsn); +} + int xrow_to_iovec(const struct xrow_header *row, struct iovec *out) { diff --git a/src/box/xrow.h b/src/box/xrow.h index 2a0a9c852..1def394e7 100644 --- a/src/box/xrow.h +++ b/src/box/xrow.h @@ -207,6 +207,52 @@ int xrow_encode_dml(const struct request *request, struct region *region, struct iovec *iov); +/** + * Encode the CONFIRM to row body and set row type to + * IPROTO_CONFIRM. + * @param row xrow header. + * @param replica_id master's instance id. + * @param lsn last confirmed lsn. + * @retval -1 on error. + * @retval 0 success. + */ +int +xrow_encode_confirm(struct xrow_header *row, uint32_t replica_id, int64_t lsn); + +/** + * Decode the CONFIRM request body. + * @param row xrow header. + * @param[out] replica_id master's instance id. + * @param[out] lsn last confirmed lsn. + * @retval -1 on error. + * @retval 0 success. + */ +int +xrow_decode_confirm(struct xrow_header *row, uint32_t *replica_id, int64_t *lsn); + +/** + * Encode the ROLLBACK row body and set row type to + * IPROTO_ROLLBACK. + * @param row xrow header. + * @param replica_id master's instance id. + * @param lsn lsn to rollback to. + * @retval -1 on error. + * @retval 0 success. + */ +int +xrow_encode_rollback(struct xrow_header *row, uint32_t replica_id, int64_t lsn); + +/** + * Decode the ROLLBACK row body. + * @param row xrow header. + * @param[out] replica_id master's instance id. + * @param[out] lsn lsn to rollback to. + * @retval -1 on error. + * @retval 0 success. + */ +int +xrow_decode_rollback(struct xrow_header *row, uint32_t *replica_id, int64_t *lsn); + /** * CALL/EVAL request. */ -- 2.21.1 (Apple Git-122.3)