From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Vladimir Davydov Subject: [PATCH v3 08/11] vinyl: simplify vylog recovery from backup Date: Sat, 14 Jul 2018 23:49:23 +0300 Message-Id: In-Reply-To: References: In-Reply-To: References: To: kostja@tarantool.org Cc: tarantool-patches@freelists.org List-ID: Since we don't create snapshot files for vylog, but instead append records written after checkpoint to the same file, we have to use the previous vylog file for backup (see vy_log_backup_path()). So when recovering from a backup we need to rotate the last vylog to keep vylog and checkpoint signatures in sync. Currently, we do it on recovery completion and we use vy_log_create() instead of vy_log_rotate() for it. This is done so that we can reuse the context that was used for recovery instead of rereading vylog for rotation. Actually, there's no point in this micro-optimization, because we rotate vylog only when recovering from a backup. Let's remove it and use vy_log_rotate() for this. Needed for #461 --- src/box/vy_log.c | 59 +++++++++++++++++++++----------------------------------- 1 file changed, 22 insertions(+), 37 deletions(-) diff --git a/src/box/vy_log.c b/src/box/vy_log.c index fbbc7a7f..2ee5553d 100644 --- a/src/box/vy_log.c +++ b/src/box/vy_log.c @@ -184,6 +184,12 @@ static int vy_recovery_process_record(struct vy_recovery *recovery, const struct vy_log_record *record); +static int +vy_log_create(const struct vclock *vclock, struct vy_recovery *recovery); + +int +vy_log_rotate(const struct vclock *vclock); + /** * Return the name of the vylog file that has the given signature. */ @@ -883,10 +889,11 @@ vy_log_begin_recovery(const struct vclock *vclock) if (xdir_scan(&vy_log.dir) < 0 && errno != ENOENT) return NULL; - struct vclock vy_log_vclock; - vclock_create(&vy_log_vclock); - if (xdir_last_vclock(&vy_log.dir, &vy_log_vclock) >= 0 && - vclock_compare(&vy_log_vclock, vclock) > 0) { + if (xdir_last_vclock(&vy_log.dir, &vy_log.last_checkpoint) < 0) + vclock_copy(&vy_log.last_checkpoint, vclock); + + int cmp = vclock_compare(&vy_log.last_checkpoint, vclock); + if (cmp > 0) { /* * Last vy_log log is newer than the last snapshot. * This can't normally happen, as vy_log is rotated @@ -896,21 +903,27 @@ vy_log_begin_recovery(const struct vclock *vclock) diag_set(ClientError, ER_MISSING_SNAPSHOT); return NULL; } + if (cmp < 0) { + /* + * Last vy_log log is older than the last snapshot. + * This happens if we are recovering from a backup. + * Rotate the log to keep its signature in sync with + * checkpoint. + */ + if (vy_log_rotate(vclock) != 0) + return NULL; + } struct vy_recovery *recovery; - recovery = vy_recovery_new(vclock_sum(&vy_log_vclock), false); + recovery = vy_recovery_new(vclock_sum(&vy_log.last_checkpoint), false); if (recovery == NULL) return NULL; vy_log.next_id = recovery->max_id + 1; vy_log.recovery = recovery; - vclock_copy(&vy_log.last_checkpoint, vclock); return recovery; } -static int -vy_log_create(const struct vclock *vclock, struct vy_recovery *recovery); - int vy_log_end_recovery(void) { @@ -931,34 +944,6 @@ vy_log_end_recovery(void) return -1; } - /* - * On backup we copy files corresponding to the most recent - * checkpoint. Since vy_log does not create snapshots of its log - * files, but instead appends records written after checkpoint - * to the most recent log file, the signature of the vy_log file - * corresponding to the last checkpoint equals the signature - * of the previous checkpoint. So upon successful recovery - * from a backup we need to rotate the log to keep checkpoint - * and vy_log signatures in sync. - */ - struct vclock *vclock = vclockset_last(&vy_log.dir.index); - if (vclock == NULL || - vclock_compare(vclock, &vy_log.last_checkpoint) != 0) { - vclock = malloc(sizeof(*vclock)); - if (vclock == NULL) { - diag_set(OutOfMemory, sizeof(*vclock), - "malloc", "struct vclock"); - return -1; - } - vclock_copy(vclock, &vy_log.last_checkpoint); - xdir_add_vclock(&vy_log.dir, vclock); - if (vy_log_create(vclock, vy_log.recovery) < 0) { - diag_log(); - say_error("failed to write `%s'", - vy_log_filename(vclock_sum(vclock))); - return -1; - } - } xdir_collect_inprogress(&vy_log.dir); vy_log.recovery = NULL; return 0; -- 2.11.0