/* * __wt_txn_release -- * Release the resources associated with the current transaction. */ void __wt_txn_release(WT_SESSION_IMPL *session) { WT_TXN *txn; WT_TXN_GLOBAL *txn_global; WT_TXN_STATE *txn_state; txn = &session->txn; txn->mod_count = 0; txn->notify = NULL; txn_global = &S2C(session)->txn_global; txn_state = &txn_global->states[session->id]; /* Clear the transaction's ID from the global table. */ WT_ASSERT(session, txn_state->id != WT_TXN_NONE && txn->id != WT_TXN_NONE); WT_PUBLISH(txn_state->id, WT_TXN_NONE); txn->id = WT_TXN_NONE; /* * Reset the transaction state to not running. * * Auto-commit transactions (identified by having active cursors) * handle this at a higher level. */ if (session->ncursors == 0) __wt_txn_release_snapshot(session); txn->isolation = session->isolation; F_CLR(txn, TXN_ERROR | TXN_OLDEST | TXN_RUNNING); }
/* * __wt_txn_release -- * Release the resources associated with the current transaction. */ void __wt_txn_release(WT_SESSION_IMPL *session) { WT_TXN *txn; WT_TXN_GLOBAL *txn_global; WT_TXN_STATE *txn_state; txn = &session->txn; txn_global = &S2C(session)->txn_global; txn_state = WT_SESSION_TXN_STATE(session); WT_ASSERT(session, txn->mod_count == 0); txn->notify = NULL; /* Clear the transaction's ID from the global table. */ if (WT_SESSION_IS_CHECKPOINT(session)) { WT_ASSERT(session, txn_state->id == WT_TXN_NONE); txn->id = txn_global->checkpoint_state.id = txn_global->checkpoint_state.pinned_id = WT_TXN_NONE; /* * Be extra careful to cleanup everything for checkpoints: once * the global checkpoint ID is cleared, we can no longer tell * if this session is doing a checkpoint. */ txn_global->checkpoint_id = 0; } else if (F_ISSET(txn, WT_TXN_HAS_ID)) { WT_ASSERT(session, !WT_TXNID_LT(txn->id, txn_global->last_running)); WT_ASSERT(session, txn_state->id != WT_TXN_NONE && txn->id != WT_TXN_NONE); WT_PUBLISH(txn_state->id, WT_TXN_NONE); txn->id = WT_TXN_NONE; } __wt_txn_clear_commit_timestamp(session); __wt_txn_clear_read_timestamp(session); /* Free the scratch buffer allocated for logging. */ __wt_logrec_free(session, &txn->logrec); /* Discard any memory from the session's stash that we can. */ WT_ASSERT(session, __wt_session_gen(session, WT_GEN_SPLIT) == 0); __wt_stash_discard(session); /* * Reset the transaction state to not running and release the snapshot. */ __wt_txn_release_snapshot(session); txn->isolation = session->isolation; /* Ensure the transaction flags are cleared on exit */ txn->flags = 0; }
/* * __wt_txn_release -- * Release the resources associated with the current transaction. */ void __wt_txn_release(WT_SESSION_IMPL *session) { WT_TXN *txn; WT_TXN_GLOBAL *txn_global; WT_TXN_STATE *txn_state; txn = &session->txn; WT_ASSERT(session, txn->mod_count == 0); txn->notify = NULL; txn_global = &S2C(session)->txn_global; txn_state = WT_SESSION_TXN_STATE(session); /* Clear the transaction's ID from the global table. */ if (WT_SESSION_IS_CHECKPOINT(session)) { WT_ASSERT(session, txn_state->id == WT_TXN_NONE); txn->id = WT_TXN_NONE; /* Clear the global checkpoint transaction IDs. */ txn_global->checkpoint_id = 0; txn_global->checkpoint_pinned = WT_TXN_NONE; } else if (F_ISSET(txn, WT_TXN_HAS_ID)) { WT_ASSERT(session, !WT_TXNID_LT(txn->id, txn_global->last_running)); WT_ASSERT(session, txn_state->id != WT_TXN_NONE && txn->id != WT_TXN_NONE); WT_PUBLISH(txn_state->id, WT_TXN_NONE); txn->id = WT_TXN_NONE; } /* Free the scratch buffer allocated for logging. */ __wt_logrec_free(session, &txn->logrec); /* Discard any memory from the session's split stash that we can. */ WT_ASSERT(session, session->split_gen == 0); if (session->split_stash_cnt > 0) __wt_split_stash_discard(session); /* * Reset the transaction state to not running and release the snapshot. */ __wt_txn_release_snapshot(session); txn->isolation = session->isolation; /* Ensure the transaction flags are cleared on exit */ txn->flags = 0; }
/* * __wt_lsm_checkpoint_chunk -- * Flush a single LSM chunk to disk. */ int __wt_lsm_checkpoint_chunk(WT_SESSION_IMPL *session, WT_LSM_TREE *lsm_tree, WT_LSM_CHUNK *chunk) { WT_DECL_RET; WT_TXN_ISOLATION saved_isolation; bool flush_set; flush_set = false; /* * If the chunk is already checkpointed, make sure it is also evicted. * Either way, there is no point trying to checkpoint it again. */ if (F_ISSET(chunk, WT_LSM_CHUNK_ONDISK) && !F_ISSET(chunk, WT_LSM_CHUNK_STABLE) && !chunk->evicted) { WT_WITH_HANDLE_LIST_LOCK(session, ret = __lsm_discard_handle(session, chunk->uri, NULL)); if (ret == 0) chunk->evicted = 1; else if (ret == EBUSY) ret = 0; else WT_RET_MSG(session, ret, "discard handle"); } if (F_ISSET(chunk, WT_LSM_CHUNK_ONDISK)) { WT_RET(__wt_verbose(session, WT_VERB_LSM, "LSM worker %s already on disk", chunk->uri)); return (0); } /* Stop if a running transaction needs the chunk. */ __wt_txn_update_oldest(session, true); if (chunk->switch_txn == WT_TXN_NONE || !__wt_txn_visible_all(session, chunk->switch_txn)) { WT_RET(__wt_verbose(session, WT_VERB_LSM, "LSM worker %s: running transaction, return", chunk->uri)); return (0); } if (!__wt_atomic_cas8(&chunk->flushing, 0, 1)) return (0); flush_set = true; WT_ERR(__wt_verbose(session, WT_VERB_LSM, "LSM worker flushing %s", chunk->uri)); /* * Flush the file before checkpointing: this is the expensive part in * terms of I/O. * * !!! * We can wait here for checkpoints and fsyncs to complete, which can * take a long time. */ if ((ret = __wt_session_get_btree( session, chunk->uri, NULL, NULL, 0)) == 0) { /* * Set read-uncommitted: we have already checked that all of the * updates in this chunk are globally visible, use the cheapest * possible check in reconciliation. */ saved_isolation = session->txn.isolation; session->txn.isolation = WT_ISO_READ_UNCOMMITTED; ret = __wt_cache_op(session, NULL, WT_SYNC_WRITE_LEAVES); session->txn.isolation = saved_isolation; WT_TRET(__wt_session_release_btree(session)); } WT_ERR(ret); WT_ERR(__wt_verbose(session, WT_VERB_LSM, "LSM worker checkpointing %s", chunk->uri)); /* * Turn on metadata tracking to ensure the checkpoint gets the * necessary handle locks. * * Ensure that we don't race with a running checkpoint: the checkpoint * lock protects against us racing with an application checkpoint in * this chunk. Don't wait for it, though: checkpoints can take a long * time, and our checkpoint operation should be very quick. */ WT_ERR(__wt_meta_track_on(session)); WT_WITH_CHECKPOINT_LOCK(session, ret, WT_WITH_SCHEMA_LOCK(session, ret, ret = __wt_schema_worker( session, chunk->uri, __wt_checkpoint, NULL, NULL, 0))); WT_TRET(__wt_meta_track_off(session, false, ret != 0)); if (ret != 0) WT_ERR_MSG(session, ret, "LSM checkpoint"); /* Now the file is written, get the chunk size. */ WT_ERR(__wt_lsm_tree_set_chunk_size(session, chunk)); /* Update the flush timestamp to help track ongoing progress. */ WT_ERR(__wt_epoch(session, &lsm_tree->last_flush_ts)); ++lsm_tree->chunks_flushed; /* Lock the tree, mark the chunk as on disk and update the metadata. */ WT_ERR(__wt_lsm_tree_writelock(session, lsm_tree)); F_SET(chunk, WT_LSM_CHUNK_ONDISK); ret = __wt_lsm_meta_write(session, lsm_tree); ++lsm_tree->dsk_gen; /* Update the throttle time. */ __wt_lsm_tree_throttle(session, lsm_tree, true); WT_TRET(__wt_lsm_tree_writeunlock(session, lsm_tree)); if (ret != 0) WT_ERR_MSG(session, ret, "LSM metadata write"); WT_PUBLISH(chunk->flushing, 0); flush_set = false; /* * Clear the no-eviction flag so the primary can be evicted and * eventually closed. Only do this once the checkpoint has succeeded: * otherwise, accessing the leaf page during the checkpoint can trigger * forced eviction. */ WT_ERR(__wt_session_get_btree(session, chunk->uri, NULL, NULL, 0)); __wt_btree_evictable(session, true); WT_ERR(__wt_session_release_btree(session)); /* Make sure we aren't pinning a transaction ID. */ __wt_txn_release_snapshot(session); WT_ERR(__wt_verbose(session, WT_VERB_LSM, "LSM worker checkpointed %s", chunk->uri)); /* Schedule a bloom filter create for our newly flushed chunk. */ if (!FLD_ISSET(lsm_tree->bloom, WT_LSM_BLOOM_OFF)) WT_ERR(__wt_lsm_manager_push_entry( session, WT_LSM_WORK_BLOOM, 0, lsm_tree)); else WT_ERR(__wt_lsm_manager_push_entry( session, WT_LSM_WORK_MERGE, 0, lsm_tree)); err: if (flush_set) WT_PUBLISH(chunk->flushing, 0); return (ret); }
/* * __sync_file -- * Flush pages for a specific file. */ static int __sync_file(WT_SESSION_IMPL *session, WT_CACHE_OP syncop) { WT_BTREE *btree; WT_CONNECTION_IMPL *conn; WT_DECL_RET; WT_PAGE *page; WT_PAGE_MODIFY *mod; WT_REF *prev, *walk; WT_TXN *txn; uint64_t internal_bytes, internal_pages, leaf_bytes, leaf_pages; uint64_t oldest_id, saved_pinned_id, time_start, time_stop; uint32_t flags; bool timer, tried_eviction; conn = S2C(session); btree = S2BT(session); prev = walk = NULL; txn = &session->txn; tried_eviction = false; time_start = time_stop = 0; /* Only visit pages in cache and don't bump page read generations. */ flags = WT_READ_CACHE | WT_READ_NO_GEN; /* * Skip all deleted pages. For a page to be marked deleted, it must * have been evicted from cache and marked clean. Checkpoint should * never instantiate deleted pages: if a truncate is not visible to the * checkpoint, the on-disk version is correct. If the truncate is * visible, we skip over the child page when writing its parent. We * check whether a truncate is visible in the checkpoint as part of * reconciling internal pages (specifically in __rec_child_modify). */ LF_SET(WT_READ_DELETED_SKIP); internal_bytes = leaf_bytes = 0; internal_pages = leaf_pages = 0; saved_pinned_id = WT_SESSION_TXN_STATE(session)->pinned_id; timer = WT_VERBOSE_ISSET(session, WT_VERB_CHECKPOINT); if (timer) time_start = __wt_clock(session); switch (syncop) { case WT_SYNC_WRITE_LEAVES: /* * Write all immediately available, dirty in-cache leaf pages. * * Writing the leaf pages is done without acquiring a high-level * lock, serialize so multiple threads don't walk the tree at * the same time. */ if (!btree->modified) return (0); __wt_spin_lock(session, &btree->flush_lock); if (!btree->modified) { __wt_spin_unlock(session, &btree->flush_lock); return (0); } /* * Save the oldest transaction ID we need to keep around. * Otherwise, in a busy system, we could be updating pages so * fast that write leaves never catches up. We deliberately * have no transaction running at this point that would keep * the oldest ID from moving forwards as we walk the tree. */ oldest_id = __wt_txn_oldest_id(session); LF_SET(WT_READ_NO_WAIT | WT_READ_SKIP_INTL); for (;;) { WT_ERR(__wt_tree_walk(session, &walk, flags)); if (walk == NULL) break; /* * Write dirty pages if nobody beat us to it. Don't * try to write hot pages (defined as pages that have * been updated since the write phase leaves started): * checkpoint will have to visit them anyway. */ page = walk->page; if (__wt_page_is_modified(page) && WT_TXNID_LT(page->modify->update_txn, oldest_id)) { if (txn->isolation == WT_ISO_READ_COMMITTED) __wt_txn_get_snapshot(session); leaf_bytes += page->memory_footprint; ++leaf_pages; WT_ERR(__wt_reconcile(session, walk, NULL, WT_REC_CHECKPOINT, NULL)); } } break; case WT_SYNC_CHECKPOINT: /* * If we are flushing a file at read-committed isolation, which * is of particular interest for flushing the metadata to make * a schema-changing operation durable, get a transactional * snapshot now. * * All changes committed up to this point should be included. * We don't update the snapshot in between pages because the * metadata shouldn't have many pages. Instead, read-committed * isolation ensures that all metadata updates completed before * the checkpoint are included. */ if (txn->isolation == WT_ISO_READ_COMMITTED) __wt_txn_get_snapshot(session); /* * We cannot check the tree modified flag in the case of a * checkpoint, the checkpoint code has already cleared it. * * Writing the leaf pages is done without acquiring a high-level * lock, serialize so multiple threads don't walk the tree at * the same time. We're holding the schema lock, but need the * lower-level lock as well. */ __wt_spin_lock(session, &btree->flush_lock); /* * In the final checkpoint pass, child pages cannot be evicted * from underneath internal pages nor can underlying blocks be * freed until the checkpoint's block lists are stable. Also, * we cannot split child pages into parents unless we know the * final pass will write a consistent view of that namespace. * Set the checkpointing flag to block such actions and wait for * any problematic eviction or page splits to complete. */ WT_ASSERT(session, btree->syncing == WT_BTREE_SYNC_OFF && btree->sync_session == NULL); btree->sync_session = session; btree->syncing = WT_BTREE_SYNC_WAIT; (void)__wt_gen_next_drain(session, WT_GEN_EVICT); btree->syncing = WT_BTREE_SYNC_RUNNING; /* Write all dirty in-cache pages. */ LF_SET(WT_READ_NO_EVICT); /* Read pages with lookaside entries and evict them asap. */ LF_SET(WT_READ_LOOKASIDE | WT_READ_WONT_NEED); for (;;) { WT_ERR(__sync_dup_walk(session, walk, flags, &prev)); WT_ERR(__wt_tree_walk(session, &walk, flags)); if (walk == NULL) break; /* * Skip clean pages, but need to make sure maximum * transaction ID is always updated. */ if (!__wt_page_is_modified(walk->page)) { if (((mod = walk->page->modify) != NULL) && mod->rec_max_txn > btree->rec_max_txn) btree->rec_max_txn = mod->rec_max_txn; if (mod != NULL && btree->rec_max_timestamp < mod->rec_max_timestamp) btree->rec_max_timestamp = mod->rec_max_timestamp; continue; } /* * Take a local reference to the page modify structure * now that we know the page is dirty. It needs to be * done in this order otherwise the page modify * structure could have been created between taking the * reference and checking modified. */ page = walk->page; /* * Write dirty pages, if we can't skip them. If we skip * a page, mark the tree dirty. The checkpoint marked it * clean and we can't skip future checkpoints until this * page is written. */ if (__sync_checkpoint_can_skip(session, page)) { __wt_tree_modify_set(session); continue; } if (WT_PAGE_IS_INTERNAL(page)) { internal_bytes += page->memory_footprint; ++internal_pages; } else { leaf_bytes += page->memory_footprint; ++leaf_pages; } /* * If the page was pulled into cache by our read, try * to evict it now. * * For eviction to have a chance, we first need to move * the walk point to the next page checkpoint will * visit. We want to avoid this code being too special * purpose, so try to reuse the ordinary eviction path. * * Regardless of whether eviction succeeds or fails, * the walk continues from the previous location. We * remember whether we tried eviction, and don't try * again. Even if eviction fails (the page may stay in * cache clean but with history that cannot be * discarded), that is not wasted effort because * checkpoint doesn't need to write the page again. */ if (!WT_PAGE_IS_INTERNAL(page) && page->read_gen == WT_READGEN_WONT_NEED && !tried_eviction) { WT_ERR_BUSY_OK( __wt_page_release_evict(session, walk)); walk = prev; prev = NULL; tried_eviction = true; continue; } tried_eviction = false; WT_ERR(__wt_reconcile( session, walk, NULL, WT_REC_CHECKPOINT, NULL)); /* * Update checkpoint IO tracking data if configured * to log verbose progress messages. */ if (conn->ckpt_timer_start.tv_sec > 0) { conn->ckpt_write_bytes += page->memory_footprint; ++conn->ckpt_write_pages; /* Periodically log checkpoint progress. */ if (conn->ckpt_write_pages % 5000 == 0) __wt_checkpoint_progress( session, false); } } break; case WT_SYNC_CLOSE: case WT_SYNC_DISCARD: WT_ERR(__wt_illegal_value(session, syncop)); break; } if (timer) { time_stop = __wt_clock(session); __wt_verbose(session, WT_VERB_CHECKPOINT, "__sync_file WT_SYNC_%s wrote: %" PRIu64 " leaf pages (%" PRIu64 "B), %" PRIu64 " internal pages (%" PRIu64 "B), and took %" PRIu64 "ms", syncop == WT_SYNC_WRITE_LEAVES ? "WRITE_LEAVES" : "CHECKPOINT", leaf_pages, leaf_bytes, internal_pages, internal_bytes, WT_CLOCKDIFF_MS(time_stop, time_start)); } err: /* On error, clear any left-over tree walk. */ WT_TRET(__wt_page_release(session, walk, flags)); WT_TRET(__wt_page_release(session, prev, flags)); /* * If we got a snapshot in order to write pages, and there was no * snapshot active when we started, release it. */ if (txn->isolation == WT_ISO_READ_COMMITTED && saved_pinned_id == WT_TXN_NONE) __wt_txn_release_snapshot(session); /* Clear the checkpoint flag. */ btree->syncing = WT_BTREE_SYNC_OFF; btree->sync_session = NULL; __wt_spin_unlock(session, &btree->flush_lock); /* * Leaves are written before a checkpoint (or as part of a file close, * before checkpointing the file). Start a flush to stable storage, * but don't wait for it. */ if (ret == 0 && syncop == WT_SYNC_WRITE_LEAVES && F_ISSET(conn, WT_CONN_CKPT_SYNC)) WT_RET(btree->bm->sync(btree->bm, session, false)); return (ret); }
/* * __sync_file -- * Flush pages for a specific file. */ static int __sync_file(WT_SESSION_IMPL *session, int syncop) { struct timespec end, start; WT_BTREE *btree; WT_DECL_RET; WT_PAGE *page; WT_PAGE_MODIFY *mod; WT_REF *walk; WT_TXN *txn; uint64_t internal_bytes, leaf_bytes; uint64_t internal_pages, leaf_pages; uint32_t flags; bool evict_reset; btree = S2BT(session); flags = WT_READ_CACHE | WT_READ_NO_GEN; walk = NULL; txn = &session->txn; internal_bytes = leaf_bytes = 0; internal_pages = leaf_pages = 0; if (WT_VERBOSE_ISSET(session, WT_VERB_CHECKPOINT)) WT_RET(__wt_epoch(session, &start)); switch (syncop) { case WT_SYNC_WRITE_LEAVES: /* * Write all immediately available, dirty in-cache leaf pages. * * Writing the leaf pages is done without acquiring a high-level * lock, serialize so multiple threads don't walk the tree at * the same time. */ if (!btree->modified) return (0); __wt_spin_lock(session, &btree->flush_lock); if (!btree->modified) { __wt_spin_unlock(session, &btree->flush_lock); return (0); } flags |= WT_READ_NO_WAIT | WT_READ_SKIP_INTL; for (walk = NULL;;) { WT_ERR(__wt_tree_walk(session, &walk, NULL, flags)); if (walk == NULL) break; /* * Write dirty pages if nobody beat us to it. Don't * try to write the hottest pages: checkpoint will have * to visit them anyway. */ page = walk->page; if (__wt_page_is_modified(page) && __wt_txn_visible_all( session, page->modify->update_txn)) { if (txn->isolation == WT_ISO_READ_COMMITTED) __wt_txn_get_snapshot(session); leaf_bytes += page->memory_footprint; ++leaf_pages; WT_ERR(__wt_reconcile(session, walk, NULL, 0)); } } break; case WT_SYNC_CHECKPOINT: /* * We cannot check the tree modified flag in the case of a * checkpoint, the checkpoint code has already cleared it. * * Writing the leaf pages is done without acquiring a high-level * lock, serialize so multiple threads don't walk the tree at * the same time. We're holding the schema lock, but need the * lower-level lock as well. */ __wt_spin_lock(session, &btree->flush_lock); /* * When internal pages are being reconciled by checkpoint their * child pages cannot disappear from underneath them or be split * into them, nor can underlying blocks be freed until the block * lists for the checkpoint are stable. Set the checkpointing * flag to block eviction of dirty pages until the checkpoint's * internal page pass is complete, then wait for any existing * eviction to complete. */ btree->checkpointing = 1; WT_FULL_BARRIER(); WT_ERR(__wt_evict_file_exclusive_on(session, &evict_reset)); if (evict_reset) __wt_evict_file_exclusive_off(session); /* Write all dirty in-cache pages. */ flags |= WT_READ_NO_EVICT; for (walk = NULL;;) { /* * If we have a page, and it was ever modified, track * the highest transaction ID in the tree. We do this * here because we want the value after reconciling * dirty pages. */ if (walk != NULL && walk->page != NULL && (mod = walk->page->modify) != NULL && WT_TXNID_LT(btree->rec_max_txn, mod->rec_max_txn)) btree->rec_max_txn = mod->rec_max_txn; WT_ERR(__wt_tree_walk(session, &walk, NULL, flags)); if (walk == NULL) break; page = walk->page; mod = page->modify; /* Skip clean pages. */ if (!__wt_page_is_modified(page)) continue; /* * Write dirty pages, unless we can be sure they only * became dirty after the checkpoint started. * * We can skip dirty pages if: * (1) they are leaf pages; * (2) there is a snapshot transaction active (which * is the case in ordinary application checkpoints * but not all internal cases); and * (3) the first dirty update on the page is * sufficiently recent that the checkpoint * transaction would skip them. * * Mark the tree dirty: the checkpoint marked it clean * and we can't skip future checkpoints until this page * is written. */ if (!WT_PAGE_IS_INTERNAL(page) && F_ISSET(txn, WT_TXN_HAS_SNAPSHOT) && WT_TXNID_LT(txn->snap_max, mod->first_dirty_txn) && mod->rec_result != WT_PM_REC_REWRITE) { __wt_page_modify_set(session, page); continue; } if (WT_PAGE_IS_INTERNAL(page)) { internal_bytes += page->memory_footprint; ++internal_pages; } else { leaf_bytes += page->memory_footprint; ++leaf_pages; } WT_ERR(__wt_reconcile(session, walk, NULL, 0)); } break; } if (WT_VERBOSE_ISSET(session, WT_VERB_CHECKPOINT)) { WT_ERR(__wt_epoch(session, &end)); WT_ERR(__wt_verbose(session, WT_VERB_CHECKPOINT, "__sync_file WT_SYNC_%s wrote:\n\t %" PRIu64 " bytes, %" PRIu64 " pages of leaves\n\t %" PRIu64 " bytes, %" PRIu64 " pages of internal\n\t" "Took: %" PRIu64 "ms", syncop == WT_SYNC_WRITE_LEAVES ? "WRITE_LEAVES" : "CHECKPOINT", leaf_bytes, leaf_pages, internal_bytes, internal_pages, WT_TIMEDIFF(end, start) / WT_MILLION)); } err: /* On error, clear any left-over tree walk. */ if (walk != NULL) WT_TRET(__wt_page_release(session, walk, flags)); if (txn->isolation == WT_ISO_READ_COMMITTED && session->ncursors == 0) __wt_txn_release_snapshot(session); if (btree->checkpointing) { /* * Update the checkpoint generation for this handle so visible * updates newer than the checkpoint can be evicted. * * This has to be published before eviction is enabled again, * so that eviction knows that the checkpoint has completed. */ WT_PUBLISH(btree->checkpoint_gen, S2C(session)->txn_global.checkpoint_gen); WT_STAT_FAST_DATA_SET(session, btree_checkpoint_generation, btree->checkpoint_gen); /* * Clear the checkpoint flag and push the change; not required, * but publishing the change means stalled eviction gets moving * as soon as possible. */ btree->checkpointing = 0; WT_FULL_BARRIER(); /* * If this tree was being skipped by the eviction server during * the checkpoint, clear the wait. */ btree->evict_walk_period = 0; /* * Wake the eviction server, in case application threads have * stalled while the eviction server decided it couldn't make * progress. Without this, application threads will be stalled * until the eviction server next wakes. */ WT_TRET(__wt_evict_server_wake(session)); } __wt_spin_unlock(session, &btree->flush_lock); /* * Leaves are written before a checkpoint (or as part of a file close, * before checkpointing the file). Start a flush to stable storage, * but don't wait for it. */ if (ret == 0 && syncop == WT_SYNC_WRITE_LEAVES) WT_RET(btree->bm->sync(btree->bm, session, true)); return (ret); }
/* * __sync_file -- * Flush pages for a specific file. */ static int __sync_file(WT_SESSION_IMPL *session, WT_CACHE_OP syncop) { struct timespec end, start; WT_BTREE *btree; WT_CONNECTION_IMPL *conn; WT_DECL_RET; WT_PAGE *page; WT_PAGE_MODIFY *mod; WT_REF *walk; WT_TXN *txn; uint64_t internal_bytes, internal_pages, leaf_bytes, leaf_pages; uint64_t oldest_id, saved_snap_min; uint32_t flags; conn = S2C(session); btree = S2BT(session); walk = NULL; txn = &session->txn; saved_snap_min = WT_SESSION_TXN_STATE(session)->snap_min; flags = WT_READ_CACHE | WT_READ_NO_GEN; internal_bytes = leaf_bytes = 0; internal_pages = leaf_pages = 0; if (WT_VERBOSE_ISSET(session, WT_VERB_CHECKPOINT)) WT_RET(__wt_epoch(session, &start)); switch (syncop) { case WT_SYNC_WRITE_LEAVES: /* * Write all immediately available, dirty in-cache leaf pages. * * Writing the leaf pages is done without acquiring a high-level * lock, serialize so multiple threads don't walk the tree at * the same time. */ if (!btree->modified) return (0); __wt_spin_lock(session, &btree->flush_lock); if (!btree->modified) { __wt_spin_unlock(session, &btree->flush_lock); return (0); } /* * Save the oldest transaction ID we need to keep around. * Otherwise, in a busy system, we could be updating pages so * fast that write leaves never catches up. We deliberately * have no transaction running at this point that would keep * the oldest ID from moving forwards as we walk the tree. */ oldest_id = __wt_txn_oldest_id(session); flags |= WT_READ_NO_WAIT | WT_READ_SKIP_INTL; for (walk = NULL;;) { WT_ERR(__wt_tree_walk(session, &walk, flags)); if (walk == NULL) break; /* * Write dirty pages if nobody beat us to it. Don't * try to write hot pages (defined as pages that have * been updated since the write phase leaves started): * checkpoint will have to visit them anyway. */ page = walk->page; if (__wt_page_is_modified(page) && WT_TXNID_LT(page->modify->update_txn, oldest_id)) { if (txn->isolation == WT_ISO_READ_COMMITTED) __wt_txn_get_snapshot(session); leaf_bytes += page->memory_footprint; ++leaf_pages; WT_ERR(__wt_reconcile(session, walk, NULL, 0)); } } break; case WT_SYNC_CHECKPOINT: /* * If we are flushing a file at read-committed isolation, which * is of particular interest for flushing the metadata to make * schema-changing operation durable, get a transactional * snapshot now. * * All changes committed up to this point should be included. * We don't update the snapshot in between pages because (a) * the metadata shouldn't be that big, and (b) if we do ever */ if (txn->isolation == WT_ISO_READ_COMMITTED) __wt_txn_get_snapshot(session); /* * We cannot check the tree modified flag in the case of a * checkpoint, the checkpoint code has already cleared it. * * Writing the leaf pages is done without acquiring a high-level * lock, serialize so multiple threads don't walk the tree at * the same time. We're holding the schema lock, but need the * lower-level lock as well. */ __wt_spin_lock(session, &btree->flush_lock); /* * In the final checkpoint pass, child pages cannot be evicted * from underneath internal pages nor can underlying blocks be * freed until the checkpoint's block lists are stable. Also, * we cannot split child pages into parents unless we know the * final pass will write a consistent view of that namespace. * Set the checkpointing flag to block such actions and wait for * any problematic eviction or page splits to complete. */ WT_PUBLISH(btree->checkpointing, WT_CKPT_PREPARE); WT_ERR(__wt_evict_file_exclusive_on(session)); __wt_evict_file_exclusive_off(session); WT_PUBLISH(btree->checkpointing, WT_CKPT_RUNNING); /* Write all dirty in-cache pages. */ flags |= WT_READ_NO_EVICT; for (walk = NULL;;) { WT_ERR(__wt_tree_walk(session, &walk, flags)); if (walk == NULL) break; /* Skip clean pages. */ if (!__wt_page_is_modified(walk->page)) continue; /* * Take a local reference to the page modify structure * now that we know the page is dirty. It needs to be * done in this order otherwise the page modify * structure could have been created between taking the * reference and checking modified. */ page = walk->page; mod = page->modify; /* * Write dirty pages, unless we can be sure they only * became dirty after the checkpoint started. * * We can skip dirty pages if: * (1) they are leaf pages; * (2) there is a snapshot transaction active (which * is the case in ordinary application checkpoints * but not all internal cases); and * (3) the first dirty update on the page is * sufficiently recent that the checkpoint * transaction would skip them. * * Mark the tree dirty: the checkpoint marked it clean * and we can't skip future checkpoints until this page * is written. */ if (!WT_PAGE_IS_INTERNAL(page) && F_ISSET(txn, WT_TXN_HAS_SNAPSHOT) && WT_TXNID_LT(txn->snap_max, mod->first_dirty_txn)) { __wt_page_modify_set(session, page); continue; } if (WT_PAGE_IS_INTERNAL(page)) { internal_bytes += page->memory_footprint; ++internal_pages; } else { leaf_bytes += page->memory_footprint; ++leaf_pages; } WT_ERR(__wt_reconcile(session, walk, NULL, 0)); } break; case WT_SYNC_CLOSE: case WT_SYNC_DISCARD: WT_ILLEGAL_VALUE_ERR(session); } if (WT_VERBOSE_ISSET(session, WT_VERB_CHECKPOINT)) { WT_ERR(__wt_epoch(session, &end)); WT_ERR(__wt_verbose(session, WT_VERB_CHECKPOINT, "__sync_file WT_SYNC_%s wrote:\n\t %" PRIu64 " bytes, %" PRIu64 " pages of leaves\n\t %" PRIu64 " bytes, %" PRIu64 " pages of internal\n\t" "Took: %" PRIu64 "ms", syncop == WT_SYNC_WRITE_LEAVES ? "WRITE_LEAVES" : "CHECKPOINT", leaf_bytes, leaf_pages, internal_bytes, internal_pages, WT_TIMEDIFF_MS(end, start))); } err: /* On error, clear any left-over tree walk. */ if (walk != NULL) WT_TRET(__wt_page_release(session, walk, flags)); /* * If we got a snapshot in order to write pages, and there was no * snapshot active when we started, release it. */ if (txn->isolation == WT_ISO_READ_COMMITTED && saved_snap_min == WT_TXN_NONE) __wt_txn_release_snapshot(session); if (btree->checkpointing != WT_CKPT_OFF) { /* * Update the checkpoint generation for this handle so visible * updates newer than the checkpoint can be evicted. * * This has to be published before eviction is enabled again, * so that eviction knows that the checkpoint has completed. */ WT_PUBLISH(btree->checkpoint_gen, conn->txn_global.checkpoint_gen); WT_STAT_FAST_DATA_SET(session, btree_checkpoint_generation, btree->checkpoint_gen); /* * Clear the checkpoint flag and push the change; not required, * but publishing the change means stalled eviction gets moving * as soon as possible. */ btree->checkpointing = WT_CKPT_OFF; WT_FULL_BARRIER(); /* * If this tree was being skipped by the eviction server during * the checkpoint, clear the wait. */ btree->evict_walk_period = 0; /* * Wake the eviction server, in case application threads have * stalled while the eviction server decided it couldn't make * progress. Without this, application threads will be stalled * until the eviction server next wakes. */ WT_TRET(__wt_evict_server_wake(session)); } __wt_spin_unlock(session, &btree->flush_lock); /* * Leaves are written before a checkpoint (or as part of a file close, * before checkpointing the file). Start a flush to stable storage, * but don't wait for it. */ if (ret == 0 && syncop == WT_SYNC_WRITE_LEAVES && F_ISSET(conn, WT_CONN_CKPT_SYNC)) WT_RET(btree->bm->sync(btree->bm, session, true)); return (ret); }
/* * __wt_txn_commit -- * Commit the current transaction. */ int __wt_txn_commit(WT_SESSION_IMPL *session, const char *cfg[]) { WT_CONFIG_ITEM cval; WT_CONNECTION_IMPL *conn; WT_DECL_RET; WT_TXN *txn; WT_TXN_OP *op; u_int i; txn = &session->txn; conn = S2C(session); WT_ASSERT(session, !F_ISSET(txn, WT_TXN_ERROR) || txn->mod_count == 0); if (!F_ISSET(txn, WT_TXN_RUNNING)) WT_RET_MSG(session, EINVAL, "No transaction is active"); /* * The default sync setting is inherited from the connection, but can * be overridden by an explicit "sync" setting for this transaction. */ WT_RET(__wt_config_gets_def(session, cfg, "sync", 0, &cval)); /* * If the user chose the default setting, check whether sync is enabled * for this transaction (either inherited or via begin_transaction). * If sync is disabled, clear the field to avoid the log write being * flushed. * * Otherwise check for specific settings. We don't need to check for * "on" because that is the default inherited from the connection. If * the user set anything in begin_transaction, we only override with an * explicit setting. */ if (cval.len == 0) { if (!FLD_ISSET(txn->txn_logsync, WT_LOG_FLUSH) && !F_ISSET(txn, WT_TXN_SYNC_SET)) txn->txn_logsync = 0; } else { /* * If the caller already set sync on begin_transaction then * they should not be using sync on commit_transaction. * Flag that as an error. */ if (F_ISSET(txn, WT_TXN_SYNC_SET)) WT_RET_MSG(session, EINVAL, "Sync already set during begin_transaction."); if (WT_STRING_MATCH("background", cval.str, cval.len)) txn->txn_logsync = WT_LOG_BACKGROUND; else if (WT_STRING_MATCH("off", cval.str, cval.len)) txn->txn_logsync = 0; /* * We don't need to check for "on" here because that is the * default to inherit from the connection setting. */ } /* Commit notification. */ if (txn->notify != NULL) WT_TRET(txn->notify->notify(txn->notify, (WT_SESSION *)session, txn->id, 1)); /* If we are logging, write a commit log record. */ if (ret == 0 && txn->mod_count > 0 && FLD_ISSET(conn->log_flags, WT_CONN_LOG_ENABLED) && !F_ISSET(session, WT_SESSION_NO_LOGGING)) { /* * We are about to block on I/O writing the log. * Release our snapshot in case it is keeping data pinned. * This is particularly important for checkpoints. */ __wt_txn_release_snapshot(session); ret = __wt_txn_log_commit(session, cfg); WT_ASSERT(session, ret == 0); } /* * If anything went wrong, roll back. * * !!! * Nothing can fail after this point. */ if (ret != 0) { WT_TRET(__wt_txn_rollback(session, cfg)); return (ret); } /* Free memory associated with updates. */ for (i = 0, op = txn->mod; i < txn->mod_count; i++, op++) __wt_txn_op_free(session, op); txn->mod_count = 0; /* * We are about to release the snapshot: copy values into any * positioned cursors so they don't point to updates that could be * freed once we don't have a transaction ID pinned. */ if (session->ncursors > 0) WT_RET(__wt_session_copy_values(session)); __wt_txn_release(session); return (0); }
/* * __wt_txn_release -- * Release the resources associated with the current transaction. */ void __wt_txn_release(WT_SESSION_IMPL *session) { WT_TXN *txn; WT_TXN_GLOBAL *txn_global; WT_TXN_STATE *txn_state; int was_oldest; txn = &session->txn; WT_ASSERT(session, txn->mod_count == 0); txn->notify = NULL; txn_global = &S2C(session)->txn_global; txn_state = WT_SESSION_TXN_STATE(session); was_oldest = 0; /* Clear the transaction's ID from the global table. */ if (WT_SESSION_IS_CHECKPOINT(session)) { WT_ASSERT(session, txn_state->id == WT_TXN_NONE); txn->id = WT_TXN_NONE; /* Clear the global checkpoint transaction IDs. */ txn_global->checkpoint_id = 0; txn_global->checkpoint_pinned = WT_TXN_NONE; } else if (F_ISSET(txn, WT_TXN_HAS_ID)) { WT_ASSERT(session, !WT_TXNID_LT(txn->id, txn_global->last_running)); WT_ASSERT(session, txn_state->id != WT_TXN_NONE && txn->id != WT_TXN_NONE); WT_PUBLISH(txn_state->id, WT_TXN_NONE); /* Quick check for the oldest transaction. */ was_oldest = (txn->id == txn_global->last_running); txn->id = WT_TXN_NONE; } /* Free the scratch buffer allocated for logging. */ __wt_logrec_free(session, &txn->logrec); /* Discard any memory from the session's split stash that we can. */ WT_ASSERT(session, session->split_gen == 0); if (session->split_stash_cnt > 0) __wt_split_stash_discard(session); /* * Reset the transaction state to not running and release the snapshot. */ __wt_txn_release_snapshot(session); txn->isolation = session->isolation; /* Ensure the transaction flags are cleared on exit */ txn->flags = 0; /* * When the oldest transaction in the system completes, bump the oldest * ID. This is racy and so not guaranteed, but in practice it keeps * the oldest ID from falling too far behind. */ if (was_oldest) __wt_txn_update_oldest(session, 1); }
/* * __wt_lsm_checkpoint_worker -- * A worker thread for an LSM tree, responsible for flushing new chunks to * disk. */ void * __wt_lsm_checkpoint_worker(void *arg) { WT_DECL_RET; WT_LSM_CHUNK *chunk; WT_LSM_TREE *lsm_tree; WT_LSM_WORKER_COOKIE cookie; WT_SESSION_IMPL *session; WT_TXN_ISOLATION saved_isolation; u_int i, j; int locked; lsm_tree = arg; session = lsm_tree->ckpt_session; WT_CLEAR(cookie); while (F_ISSET(lsm_tree, WT_LSM_TREE_WORKING)) { if (F_ISSET(lsm_tree, WT_LSM_TREE_NEED_SWITCH)) { WT_WITH_SCHEMA_LOCK(session, ret = __wt_lsm_tree_switch(session, lsm_tree)); WT_ERR(ret); } WT_ERR(__lsm_copy_chunks(session, lsm_tree, &cookie, 0)); /* Write checkpoints in all completed files. */ for (i = 0, j = 0; i < cookie.nchunks - 1; i++) { if (!F_ISSET(lsm_tree, WT_LSM_TREE_WORKING)) goto err; if (F_ISSET(lsm_tree, WT_LSM_TREE_NEED_SWITCH)) break; chunk = cookie.chunk_array[i]; /* Stop if a running transaction needs the chunk. */ __wt_txn_update_oldest(session); if (!__wt_txn_visible_all(session, chunk->txnid_max)) break; /* * If the chunk is already checkpointed, make sure it * is also evicted. Either way, there is no point * trying to checkpoint it again. */ if (F_ISSET_ATOMIC(chunk, WT_LSM_CHUNK_ONDISK)) { if (F_ISSET_ATOMIC(chunk, WT_LSM_CHUNK_EVICTED)) continue; if ((ret = __lsm_discard_handle( session, chunk->uri, NULL)) == 0) F_SET_ATOMIC( chunk, WT_LSM_CHUNK_EVICTED); else if (ret == EBUSY) ret = 0; else WT_ERR_MSG(session, ret, "discard handle"); continue; } WT_VERBOSE_ERR(session, lsm, "LSM worker flushing %u", i); /* * Flush the file before checkpointing: this is the * expensive part in terms of I/O: do it without * holding the schema lock. * * Use the special eviction isolation level to avoid * interfering with an application checkpoint: we have * already checked that all of the updates in this * chunk are globally visible. * * !!! We can wait here for checkpoints and fsyncs to * complete, which can be a long time. * * Don't keep waiting for the lock if application * threads are waiting for a switch. Don't skip * flushing the leaves either: that just means we'll * hold the schema lock for (much) longer, which blocks * the world. */ WT_ERR(__wt_session_get_btree( session, chunk->uri, NULL, NULL, 0)); for (locked = 0; !locked && ret == 0 && !F_ISSET(lsm_tree, WT_LSM_TREE_NEED_SWITCH);) { if ((ret = __wt_spin_trylock(session, &S2C(session)->checkpoint_lock)) == 0) locked = 1; else if (ret == EBUSY) { __wt_yield(); ret = 0; } } if (locked) { saved_isolation = session->txn.isolation; session->txn.isolation = TXN_ISO_EVICTION; ret = __wt_bt_cache_op( session, NULL, WT_SYNC_WRITE_LEAVES); session->txn.isolation = saved_isolation; __wt_spin_unlock( session, &S2C(session)->checkpoint_lock); } WT_TRET(__wt_session_release_btree(session)); WT_ERR(ret); if (F_ISSET(lsm_tree, WT_LSM_TREE_NEED_SWITCH)) break; WT_VERBOSE_ERR(session, lsm, "LSM worker checkpointing %u", i); WT_WITH_SCHEMA_LOCK(session, ret = __wt_schema_worker(session, chunk->uri, __wt_checkpoint, NULL, NULL, 0)); if (ret != 0) { __wt_err(session, ret, "LSM checkpoint"); break; } WT_ERR(__wt_lsm_tree_set_chunk_size(session, chunk)); /* * Clear the "cache resident" flag so the primary can * be evicted and eventually closed. Only do this once * the checkpoint has succeeded: otherwise, accessing * the leaf page during the checkpoint can trigger * forced eviction. */ WT_ERR(__wt_session_get_btree( session, chunk->uri, NULL, NULL, 0)); __wt_btree_evictable(session, 1); WT_ERR(__wt_session_release_btree(session)); ++j; WT_ERR(__wt_lsm_tree_lock(session, lsm_tree, 1)); F_SET_ATOMIC(chunk, WT_LSM_CHUNK_ONDISK); ret = __wt_lsm_meta_write(session, lsm_tree); ++lsm_tree->dsk_gen; /* Update the throttle time. */ __wt_lsm_tree_throttle(session, lsm_tree); WT_TRET(__wt_lsm_tree_unlock(session, lsm_tree)); /* Make sure we aren't pinning a transaction ID. */ __wt_txn_release_snapshot(session); if (ret != 0) { __wt_err(session, ret, "LSM checkpoint metadata write"); break; } WT_VERBOSE_ERR(session, lsm, "LSM worker checkpointed %u", i); } __lsm_unpin_chunks(session, &cookie); if (j == 0 && F_ISSET(lsm_tree, WT_LSM_TREE_WORKING) && !F_ISSET(lsm_tree, WT_LSM_TREE_NEED_SWITCH)) WT_ERR_TIMEDOUT_OK(__wt_cond_wait( session, lsm_tree->work_cond, 100000)); } err: __lsm_unpin_chunks(session, &cookie); __wt_free(session, cookie.chunk_array); /* * The thread will only exit with failure if we run out of memory or * there is some other system driven failure. We can't keep going * after such a failure - ensure WiredTiger shuts down. */ if (ret != 0 && ret != WT_NOTFOUND) WT_PANIC_ERR(session, ret, "Shutting down LSM checkpoint utility thread"); return (NULL); }
/* * __wt_txn_commit -- * Commit the current transaction. */ int __wt_txn_commit(WT_SESSION_IMPL *session, const char *cfg[]) { WT_CONFIG_ITEM cval; WT_CONNECTION_IMPL *conn; WT_DECL_RET; WT_TXN *txn; WT_TXN_GLOBAL *txn_global; WT_TXN_OP *op; u_int i; bool locked, readonly; #ifdef HAVE_TIMESTAMPS wt_timestamp_t prev_commit_timestamp, ts; bool update_timestamp; #endif txn = &session->txn; conn = S2C(session); txn_global = &conn->txn_global; locked = false; WT_ASSERT(session, F_ISSET(txn, WT_TXN_RUNNING)); WT_ASSERT(session, !F_ISSET(txn, WT_TXN_ERROR) || txn->mod_count == 0); readonly = txn->mod_count == 0; /* * Look for a commit timestamp. */ WT_ERR( __wt_config_gets_def(session, cfg, "commit_timestamp", 0, &cval)); if (cval.len != 0) { #ifdef HAVE_TIMESTAMPS WT_ERR(__wt_txn_parse_timestamp(session, "commit", &ts, &cval)); WT_ERR(__wt_timestamp_validate(session, "commit", &ts, &cval, true, true, true)); __wt_timestamp_set(&txn->commit_timestamp, &ts); __wt_txn_set_commit_timestamp(session); #else WT_ERR_MSG(session, EINVAL, "commit_timestamp requires a " "version of WiredTiger built with timestamp support"); #endif } #ifdef HAVE_TIMESTAMPS /* * Debugging checks on timestamps, if user requested them. */ if (F_ISSET(txn, WT_TXN_TS_COMMIT_ALWAYS) && !F_ISSET(txn, WT_TXN_HAS_TS_COMMIT) && txn->mod_count != 0) WT_ERR_MSG(session, EINVAL, "commit_timestamp required and " "none set on this transaction"); if (F_ISSET(txn, WT_TXN_TS_COMMIT_NEVER) && F_ISSET(txn, WT_TXN_HAS_TS_COMMIT) && txn->mod_count != 0) WT_ERR_MSG(session, EINVAL, "no commit_timestamp required and " "timestamp set on this transaction"); #endif /* * The default sync setting is inherited from the connection, but can * be overridden by an explicit "sync" setting for this transaction. */ WT_ERR(__wt_config_gets_def(session, cfg, "sync", 0, &cval)); /* * If the user chose the default setting, check whether sync is enabled * for this transaction (either inherited or via begin_transaction). * If sync is disabled, clear the field to avoid the log write being * flushed. * * Otherwise check for specific settings. We don't need to check for * "on" because that is the default inherited from the connection. If * the user set anything in begin_transaction, we only override with an * explicit setting. */ if (cval.len == 0) { if (!FLD_ISSET(txn->txn_logsync, WT_LOG_SYNC_ENABLED) && !F_ISSET(txn, WT_TXN_SYNC_SET)) txn->txn_logsync = 0; } else { /* * If the caller already set sync on begin_transaction then * they should not be using sync on commit_transaction. * Flag that as an error. */ if (F_ISSET(txn, WT_TXN_SYNC_SET)) WT_ERR_MSG(session, EINVAL, "Sync already set during begin_transaction"); if (WT_STRING_MATCH("background", cval.str, cval.len)) txn->txn_logsync = WT_LOG_BACKGROUND; else if (WT_STRING_MATCH("off", cval.str, cval.len)) txn->txn_logsync = 0; /* * We don't need to check for "on" here because that is the * default to inherit from the connection setting. */ } /* Commit notification. */ if (txn->notify != NULL) WT_ERR(txn->notify->notify(txn->notify, (WT_SESSION *)session, txn->id, 1)); /* * We are about to release the snapshot: copy values into any * positioned cursors so they don't point to updates that could be * freed once we don't have a snapshot. */ if (session->ncursors > 0) { WT_DIAGNOSTIC_YIELD; WT_ERR(__wt_session_copy_values(session)); } /* If we are logging, write a commit log record. */ if (txn->logrec != NULL && FLD_ISSET(conn->log_flags, WT_CONN_LOG_ENABLED) && !F_ISSET(session, WT_SESSION_NO_LOGGING)) { /* * We are about to block on I/O writing the log. * Release our snapshot in case it is keeping data pinned. * This is particularly important for checkpoints. */ __wt_txn_release_snapshot(session); /* * We hold the visibility lock for reading from the time * we write our log record until the time we release our * transaction so that the LSN any checkpoint gets will * always reflect visible data. */ __wt_readlock(session, &txn_global->visibility_rwlock); locked = true; WT_ERR(__wt_txn_log_commit(session, cfg)); } /* Note: we're going to commit: nothing can fail after this point. */ /* Process and free updates. */ for (i = 0, op = txn->mod; i < txn->mod_count; i++, op++) { switch (op->type) { case WT_TXN_OP_BASIC: case WT_TXN_OP_BASIC_TS: case WT_TXN_OP_INMEM: /* * Switch reserved operations to abort to * simplify obsolete update list truncation. */ if (op->u.upd->type == WT_UPDATE_RESERVED) { op->u.upd->txnid = WT_TXN_ABORTED; break; } /* * Writes to the lookaside file can be evicted as soon * as they commit. */ if (conn->cache->las_fileid != 0 && op->fileid == conn->cache->las_fileid) { op->u.upd->txnid = WT_TXN_NONE; break; } #ifdef HAVE_TIMESTAMPS if (F_ISSET(txn, WT_TXN_HAS_TS_COMMIT) && op->type != WT_TXN_OP_BASIC_TS) { WT_ASSERT(session, op->fileid != WT_METAFILE_ID); __wt_timestamp_set(&op->u.upd->timestamp, &txn->commit_timestamp); } #endif break; case WT_TXN_OP_REF: #ifdef HAVE_TIMESTAMPS if (F_ISSET(txn, WT_TXN_HAS_TS_COMMIT)) __wt_timestamp_set( &op->u.ref->page_del->timestamp, &txn->commit_timestamp); #endif break; case WT_TXN_OP_TRUNCATE_COL: case WT_TXN_OP_TRUNCATE_ROW: /* Other operations don't need timestamps. */ break; } __wt_txn_op_free(session, op); } txn->mod_count = 0; #ifdef HAVE_TIMESTAMPS /* * Track the largest commit timestamp we have seen. * * We don't actually clear the local commit timestamp, just the flag. * That said, we can't update the global commit timestamp until this * transaction is visible, which happens when we release it. */ update_timestamp = F_ISSET(txn, WT_TXN_HAS_TS_COMMIT); #endif __wt_txn_release(session); if (locked) __wt_readunlock(session, &txn_global->visibility_rwlock); #ifdef HAVE_TIMESTAMPS /* First check if we've already committed something in the future. */ if (update_timestamp) { WT_WITH_TIMESTAMP_READLOCK(session, &txn_global->rwlock, __wt_timestamp_set( &prev_commit_timestamp, &txn_global->commit_timestamp)); update_timestamp = __wt_timestamp_cmp( &txn->commit_timestamp, &prev_commit_timestamp) > 0; } /* * If it looks like we need to move the global commit timestamp, * write lock and re-check. */ if (update_timestamp) { #if WT_TIMESTAMP_SIZE == 8 while (__wt_timestamp_cmp( &txn->commit_timestamp, &prev_commit_timestamp) > 0) { if (__wt_atomic_cas64( &txn_global->commit_timestamp.val, prev_commit_timestamp.val, txn->commit_timestamp.val)) { txn_global->has_commit_timestamp = true; break; } __wt_timestamp_set( &prev_commit_timestamp, &txn_global->commit_timestamp); } #else __wt_writelock(session, &txn_global->rwlock); if (__wt_timestamp_cmp(&txn->commit_timestamp, &txn_global->commit_timestamp) > 0) { __wt_timestamp_set(&txn_global->commit_timestamp, &txn->commit_timestamp); txn_global->has_commit_timestamp = true; } __wt_writeunlock(session, &txn_global->rwlock); #endif } #endif /* * We're between transactions, if we need to block for eviction, it's * a good time to do so. Note that we must ignore any error return * because the user's data is committed. */ if (!readonly) (void)__wt_cache_eviction_check(session, false, false, NULL); return (0); err: /* * If anything went wrong, roll back. * * !!! * Nothing can fail after this point. */ if (locked) __wt_readunlock(session, &txn_global->visibility_rwlock); WT_TRET(__wt_txn_rollback(session, cfg)); return (ret); }
/* * __wt_lsm_checkpoint_chunk -- * Flush a single LSM chunk to disk. */ int __wt_lsm_checkpoint_chunk(WT_SESSION_IMPL *session, WT_LSM_TREE *lsm_tree, WT_LSM_CHUNK *chunk) { WT_DECL_RET; WT_TXN_ISOLATION saved_isolation; /* * If the chunk is already checkpointed, make sure it is also evicted. * Either way, there is no point trying to checkpoint it again. */ if (F_ISSET(chunk, WT_LSM_CHUNK_ONDISK) && !F_ISSET(chunk, WT_LSM_CHUNK_STABLE) && !chunk->evicted) { if ((ret = __lsm_discard_handle( session, chunk->uri, NULL)) == 0) chunk->evicted = 1; else if (ret == EBUSY) ret = 0; else WT_RET_MSG(session, ret, "discard handle"); } if (F_ISSET(chunk, WT_LSM_CHUNK_ONDISK)) { WT_RET(__wt_verbose(session, WT_VERB_LSM, "LSM worker %s already on disk", chunk->uri)); return (0); } /* Stop if a running transaction needs the chunk. */ __wt_txn_update_oldest(session); if (chunk->switch_txn == WT_TXN_NONE || !__wt_txn_visible_all(session, chunk->switch_txn)) { WT_RET(__wt_verbose(session, WT_VERB_LSM, "LSM worker %s: running transaction, return", chunk->uri)); return (0); } WT_RET(__wt_verbose(session, WT_VERB_LSM, "LSM worker flushing %s", chunk->uri)); /* * Flush the file before checkpointing: this is the expensive part in * terms of I/O. * * Use the special eviction isolation level to avoid interfering with * an application checkpoint: we have already checked that all of the * updates in this chunk are globally visible. * * !!! We can wait here for checkpoints and fsyncs to complete, which * can be a long time. */ if ((ret = __wt_session_get_btree( session, chunk->uri, NULL, NULL, 0)) == 0) { saved_isolation = session->txn.isolation; session->txn.isolation = TXN_ISO_EVICTION; ret = __wt_cache_op(session, NULL, WT_SYNC_WRITE_LEAVES); session->txn.isolation = saved_isolation; WT_TRET(__wt_session_release_btree(session)); } WT_RET(ret); WT_RET(__wt_verbose(session, WT_VERB_LSM, "LSM worker checkpointing %s", chunk->uri)); WT_WITH_SCHEMA_LOCK(session, ret = __wt_schema_worker(session, chunk->uri, __wt_checkpoint, NULL, NULL, 0)); if (ret != 0) WT_RET_MSG(session, ret, "LSM checkpoint"); /* Now the file is written, get the chunk size. */ WT_RET(__wt_lsm_tree_set_chunk_size(session, chunk)); /* Update the flush timestamp to help track ongoing progress. */ WT_RET(__wt_epoch(session, &lsm_tree->last_flush_ts)); /* Lock the tree, mark the chunk as on disk and update the metadata. */ WT_RET(__wt_lsm_tree_writelock(session, lsm_tree)); F_SET(chunk, WT_LSM_CHUNK_ONDISK); ret = __wt_lsm_meta_write(session, lsm_tree); ++lsm_tree->dsk_gen; /* Update the throttle time. */ __wt_lsm_tree_throttle(session, lsm_tree, 1); WT_TRET(__wt_lsm_tree_writeunlock(session, lsm_tree)); if (ret != 0) WT_RET_MSG(session, ret, "LSM metadata write"); /* * Clear the no-eviction flag so the primary can be evicted and * eventually closed. Only do this once the checkpoint has succeeded: * otherwise, accessing the leaf page during the checkpoint can trigger * forced eviction. */ WT_RET(__wt_session_get_btree(session, chunk->uri, NULL, NULL, 0)); __wt_btree_evictable(session, 1); WT_RET(__wt_session_release_btree(session)); /* Make sure we aren't pinning a transaction ID. */ __wt_txn_release_snapshot(session); WT_RET(__wt_verbose(session, WT_VERB_LSM, "LSM worker checkpointed %s", chunk->uri)); /* Schedule a bloom filter create for our newly flushed chunk. */ if (!FLD_ISSET(lsm_tree->bloom, WT_LSM_BLOOM_OFF)) WT_RET(__wt_lsm_manager_push_entry( session, WT_LSM_WORK_BLOOM, 0, lsm_tree)); else WT_RET(__wt_lsm_manager_push_entry( session, WT_LSM_WORK_MERGE, 0, lsm_tree)); return (0); }