diff options
Diffstat (limited to 'src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c')
| -rw-r--r-- | src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c | 82 |
1 files changed, 34 insertions, 48 deletions
diff --git a/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c b/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c index 97c83c47414..d3d9c2b4dfb 100644 --- a/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c +++ b/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c @@ -105,13 +105,11 @@ __txn_abort_newer_update( first_upd = upd->next; } else if (rollback_timestamp < upd->durable_ts) { /* - * If any updates are aborted, all newer updates - * better be aborted as well. + * If any updates are aborted, all newer updates better be aborted as well. * - * Timestamp ordering relies on the validations at - * the time of commit. Thus if the table is not - * configured for key consistency check, the - * the timestamps could be out of order here. + * Timestamp ordering relies on the validations at the time of commit. Thus if the table + * is not configured for key consistency check, the timestamps could be out of order + * here. */ WT_ASSERT(session, !FLD_ISSET(S2BT(session)->assert_flags, WT_ASSERT_COMMIT_TS_KEYS) || upd == first_upd); @@ -222,34 +220,29 @@ __txn_abort_newer_updates(WT_SESSION_IMPL *session, WT_REF *ref, wt_timestamp_t { WT_DECL_RET; WT_PAGE *page; + WT_PAGE_LOOKASIDE *page_las; uint32_t read_flags; bool local_read; /* - * If we created a page image with updates the need to be rolled back, - * read the history into cache now and make sure the page is marked - * dirty. Otherwise, the history we need could be swept from the - * lookaside table before the page is read because the lookaside sweep - * code has no way to tell that the page image is invalid. + * If we created a page image with updates that need to be rolled back, read the history into + * cache now and make sure the page is marked dirty. Otherwise, the history we need could be + * swept from the lookaside table before the page is read because the lookaside sweep code has + * no way to tell that the page image is invalid. * - * So, if there is lookaside history for a page, first check if the - * history needs to be rolled back make sure that history is loaded - * into cache. That is, if skew_newest is true, so the disk image - * potentially contained unstable updates, and the history is more - * recent than the rollback timestamp. + * So, if there is lookaside history for a page, first check if the history needs to be rolled + * back then ensure the history is loaded into cache. * - * Also, we have separately discarded any lookaside history more recent - * than the rollback timestamp. For page_las structures in cache, - * reset any future timestamps back to the rollback timestamp. This - * allows those structures to be discarded once the rollback timestamp - * is stable (crucially for tests, they can be discarded if the - * connection is closed right after a rollback_to_stable call). + * Also, we have separately discarded any lookaside history more recent than the rollback + * timestamp. For page_las structures in cache, reset any future timestamps back to the rollback + * timestamp. This allows those structures to be discarded once the rollback timestamp is stable + * (crucially for tests, they can be discarded if the connection is closed right after a + * rollback_to_stable call). */ local_read = false; read_flags = WT_READ_WONT_NEED; - if (ref->page_las != NULL) { - if (ref->page_las->skew_newest && - rollback_timestamp < ref->page_las->unstable_durable_timestamp) { + if ((page_las = ref->page_las) != NULL) { + if (rollback_timestamp < page_las->max_ondisk_ts) { /* * Make sure we get back a page with history, not a limbo page. */ @@ -258,13 +251,10 @@ __txn_abort_newer_updates(WT_SESSION_IMPL *session, WT_REF *ref, wt_timestamp_t WT_ASSERT(session, ref->state != WT_REF_LIMBO && ref->page != NULL && __wt_page_is_modified(ref->page)); local_read = true; + page_las->max_ondisk_ts = rollback_timestamp; } - if (ref->page_las->max_timestamp > rollback_timestamp) - ref->page_las->max_timestamp = rollback_timestamp; - if (ref->page_las->unstable_durable_timestamp > rollback_timestamp) - ref->page_las->unstable_durable_timestamp = rollback_timestamp; - if (ref->page_las->unstable_timestamp > rollback_timestamp) - ref->page_las->unstable_timestamp = rollback_timestamp; + if (rollback_timestamp < page_las->min_skipped_ts) + page_las->min_skipped_ts = rollback_timestamp; } /* Review deleted page saved to the ref */ @@ -272,18 +262,14 @@ __txn_abort_newer_updates(WT_SESSION_IMPL *session, WT_REF *ref, wt_timestamp_t WT_ERR(__wt_delete_page_rollback(session, ref)); /* - * If we have a ref with no page, or the page is clean, there is - * nothing to roll back. + * If we have a ref with no page, or the page is clean, there is nothing to roll back. * - * This check for a clean page is partly an optimization (checkpoint - * only marks pages clean when they have no unwritten updates so - * there's no point visiting them again), but also covers a corner case - * of a checkpoint with use_timestamp=false. Such a checkpoint - * effectively moves the stable timestamp forward, because changes that - * are written in the checkpoint cannot be reliably rolled back. The - * actual stable timestamp doesn't change, though, so if we try to roll - * back clean pages the in-memory tree can get out of sync with the - * on-disk tree. + * This check for a clean page is partly an optimization (checkpoint only marks pages clean when + * they have no unwritten updates so there's no point visiting them again), but also covers a + * corner case of a checkpoint with use_timestamp=false. Such a checkpoint effectively moves the + * stable timestamp forward, because changes that are written in the checkpoint cannot be + * reliably rolled back. The actual stable timestamp doesn't change, though, so if we try to + * roll back clean pages the in-memory tree can get out of sync with the on-disk tree. */ if ((page = ref->page) == NULL || !__wt_page_is_modified(page)) goto err; @@ -436,6 +422,7 @@ __txn_rollback_to_stable_check(WT_SESSION_IMPL *session) conn = S2C(session); txn_global = &conn->txn_global; + if (!txn_global->has_stable_timestamp) WT_RET_MSG(session, EINVAL, "rollback_to_stable requires a stable timestamp"); @@ -472,13 +459,12 @@ __txn_rollback_to_stable(WT_SESSION_IMPL *session, const char *cfg[]) WT_STAT_CONN_INCR(session, txn_rollback_to_stable); /* - * Mark that a rollback operation is in progress and wait for eviction - * to drain. This is necessary because lookaside eviction uses - * transactions and causes the check for a quiescent system to fail. + * Mark that a rollback operation is in progress and wait for eviction to drain. This is + * necessary because lookaside eviction uses transactions and causes the check for a quiescent + * system to fail. * - * Configuring lookaside eviction off isn't atomic, safe because the - * flag is only otherwise set when closing down the database. Assert - * to avoid confusion in the future. + * Configuring lookaside eviction off isn't atomic, safe because the flag is only otherwise set + * when closing down the database. Assert to avoid confusion in the future. */ WT_ASSERT(session, !F_ISSET(conn, WT_CONN_EVICTION_NO_LOOKASIDE)); F_SET(conn, WT_CONN_EVICTION_NO_LOOKASIDE); |