vacuum: move variable into scope of use in ctdb_process_delete_list()
[ctdb.git] / server / ctdb_vacuum.c
index 5d93c8adaea5a939c3d119972c0712707048384c..9611a1514ca1a6fc8465aeb7004e380a8345576a 100644 (file)
@@ -60,9 +60,9 @@ struct vacuum_data {
        struct ctdb_context *ctdb;
        struct ctdb_db_context *ctdb_db;
        struct tdb_context *dest_db;
-       trbt_tree_t *delete_tree;
+       trbt_tree_t *delete_list;
        uint32_t delete_count;
-       struct ctdb_marshall_buffer **list;
+       struct ctdb_marshall_buffer **vacuum_fetch_list;
        struct timeval start;
        bool traverse_error;
        bool vacuum;
@@ -70,16 +70,21 @@ struct vacuum_data {
        uint32_t vacuumed;
        uint32_t copied;
        uint32_t fast_added_to_vacuum_fetch_list;
-       uint32_t fast_added_to_delete_tree;
+       uint32_t fast_added_to_delete_list;
        uint32_t fast_deleted;
        uint32_t fast_skipped;
        uint32_t fast_error;
        uint32_t fast_total;
        uint32_t full_added_to_vacuum_fetch_list;
-       uint32_t full_added_to_delete_tree;
+       uint32_t full_added_to_delete_list;
        uint32_t full_skipped;
        uint32_t full_error;
        uint32_t full_total;
+       uint32_t delete_left;
+       uint32_t delete_remote_error;
+       uint32_t delete_local_error;
+       uint32_t delete_deleted;
+       uint32_t delete_skipped;
 };
 
 /* this structure contains the information for one record to be deleted */
@@ -88,6 +93,7 @@ struct delete_record_data {
        struct ctdb_db_context *ctdb_db;
        struct ctdb_ltdb_header hdr;
        TDB_DATA key;
+       uint8_t keydata[1];
 };
 
 struct delete_records_list {
@@ -105,21 +111,22 @@ static int insert_delete_record_data_into_tree(struct ctdb_context *ctdb,
 {
        struct delete_record_data *dd;
        uint32_t hash;
+       size_t len;
 
-       dd = talloc_zero(tree, struct delete_record_data);
+       len = offsetof(struct delete_record_data, keydata) + key.dsize;
+
+       dd = (struct delete_record_data *)talloc_size(tree, len);
        if (dd == NULL) {
                DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
                return -1;
        }
+       talloc_set_name_const(dd, "struct delete_record_data");
 
        dd->ctdb      = ctdb;
        dd->ctdb_db   = ctdb_db;
        dd->key.dsize = key.dsize;
-       dd->key.dptr  = talloc_memdup(dd, key.dptr, key.dsize);
-       if (dd->key.dptr == NULL) {
-               DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
-               return -1;
-       }
+       dd->key.dptr  = dd->keydata;
+       memcpy(dd->keydata, key.dptr, key.dsize);
 
        dd->hdr = *hdr;
 
@@ -130,7 +137,7 @@ static int insert_delete_record_data_into_tree(struct ctdb_context *ctdb,
        return 0;
 }
 
-static int add_record_to_delete_tree(struct vacuum_data *vdata, TDB_DATA key,
+static int add_record_to_delete_list(struct vacuum_data *vdata, TDB_DATA key,
                                     struct ctdb_ltdb_header *hdr)
 {
        struct ctdb_context *ctdb = vdata->ctdb;
@@ -140,13 +147,13 @@ static int add_record_to_delete_tree(struct vacuum_data *vdata, TDB_DATA key,
 
        hash = (uint32_t)tdb_jenkins_hash(&key);
 
-       if (trbt_lookup32(vdata->delete_tree, hash)) {
+       if (trbt_lookup32(vdata->delete_list, hash)) {
                DEBUG(DEBUG_INFO, (__location__ " Hash collission when vacuuming, skipping this record.\n"));
                return 0;
        }
 
        ret = insert_delete_record_data_into_tree(ctdb, ctdb_db,
-                                                 vdata->delete_tree,
+                                                 vdata->delete_list,
                                                  hdr, key);
        if (ret != 0) {
                return -1;
@@ -168,27 +175,30 @@ static int add_record_to_vacuum_fetch_list(struct vacuum_data *vdata,
        struct ctdb_rec_data *rec;
        uint32_t lmaster;
        size_t old_size;
+       struct ctdb_marshall_buffer *vfl;
 
        lmaster = ctdb_lmaster(ctdb, &key);
 
-       rec = ctdb_marshall_record(vdata->list[lmaster], ctdb->pnn, key, NULL, tdb_null);
+       vfl = vdata->vacuum_fetch_list[lmaster];
+
+       rec = ctdb_marshall_record(vfl, ctdb->pnn, key, NULL, tdb_null);
        if (rec == NULL) {
                DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
                vdata->traverse_error = true;
                return -1;
        }
 
-       old_size = talloc_get_size(vdata->list[lmaster]);
-       vdata->list[lmaster] = talloc_realloc_size(NULL, vdata->list[lmaster],
-                                                  old_size + rec->length);
-       if (vdata->list[lmaster] == NULL) {
+       old_size = talloc_get_size(vfl);
+       vfl = talloc_realloc_size(NULL, vfl, old_size + rec->length);
+       if (vfl == NULL) {
                DEBUG(DEBUG_ERR,(__location__ " Failed to expand\n"));
                vdata->traverse_error = true;
                return -1;
        }
+       vdata->vacuum_fetch_list[lmaster] = vfl;
 
-       vdata->list[lmaster]->count++;
-       memcpy(old_size+(uint8_t *)vdata->list[lmaster], rec, rec->length);
+       vfl->count++;
+       memcpy(old_size+(uint8_t *)vfl, rec, rec->length);
        talloc_free(rec);
 
        vdata->total++;
@@ -244,11 +254,11 @@ static int vacuum_traverse(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data,
                 * We are both lmaster and dmaster, and the record is empty.
                 * So we should be able to delete it.
                 */
-               res = add_record_to_delete_tree(vdata, key, hdr);
+               res = add_record_to_delete_list(vdata, key, hdr);
                if (res != 0) {
                        vdata->full_error++;
                } else {
-                       vdata->full_added_to_delete_tree++;
+                       vdata->full_added_to_delete_list++;
                }
        } else {
                /*
@@ -325,12 +335,16 @@ static int delete_queue_traverse(void *param, void *data)
        struct ctdb_ltdb_header *header;
        TDB_DATA tdb_data;
        uint32_t lmaster;
+       uint32_t hash = ctdb_hash(&(dd->key));
 
        vdata->fast_total++;
 
        res = tdb_chainlock(ctdb_db->ltdb->tdb, dd->key);
        if (res != 0) {
-               DEBUG(DEBUG_ERR, (__location__ " Error getting chainlock.\n"));
+               DEBUG(DEBUG_ERR,
+                     (__location__ " Error getting chainlock on record with "
+                      "key hash [0x%08x] on database db[%s].\n",
+                      hash, ctdb_db->db_name));
                vdata->fast_error++;
                return 0;
        }
@@ -353,7 +367,6 @@ static int delete_queue_traverse(void *param, void *data)
                goto skipped;
        }
 
-
        if (header->rsn != dd->hdr.rsn) {
                /*
                 * The record has been migrated off the node and back again.
@@ -389,7 +402,7 @@ static int delete_queue_traverse(void *param, void *data)
 
        /* use header->flags or dd->hdr.flags ?? */
        if (dd->hdr.flags & CTDB_REC_FLAG_MIGRATED_WITH_DATA) {
-               res = add_record_to_delete_tree(vdata, dd->key, &dd->hdr);
+               res = add_record_to_delete_list(vdata, dd->key, &dd->hdr);
 
                if (res != 0) {
                        DEBUG(DEBUG_ERR,
@@ -397,17 +410,22 @@ static int delete_queue_traverse(void *param, void *data)
                               "of records for deletion on lmaster.\n"));
                        vdata->fast_error++;
                } else {
-                       vdata->fast_added_to_delete_tree++;
+                       vdata->fast_added_to_delete_list++;
                }
        } else {
                res = tdb_delete(ctdb_db->ltdb->tdb, dd->key);
 
                if (res != 0) {
                        DEBUG(DEBUG_ERR,
-                             (__location__ " Error deleting record from local "
-                              "data base.\n"));
+                             (__location__ " Error deleting record with key "
+                              "hash [0x%08x] from local data base db[%s].\n",
+                              hash, ctdb_db->db_name));
                        vdata->fast_error++;
                } else {
+                       DEBUG(DEBUG_DEBUG,
+                             (__location__ " Deleted record with key hash "
+                              "[0x%08x] from local data base db[%s].\n",
+                              hash, ctdb_db->db_name));
                        vdata->fast_deleted++;
                }
        }
@@ -427,98 +445,140 @@ done:
 }
 
 /**
- * Vacuum a DB:
- *  - Always do the fast vacuuming run, which traverses
- *    the in-memory delete queue: these records have been
- *    scheduled for deletion.
- *  - Only if explicitly requested, the database is traversed
- *    in order to use the traditional heuristics on empty records
- *    to trigger deletion.
- *    This is done only every VacuumFastPathCount'th vacuuming run.
- *
- * The traverse runs fill two lists:
- *
- * - The delete_list:
- *   This is the list of empty records the current
- *   node is lmaster and dmaster for. These records are later
- *   deleted first on other nodes and then locally.
- *
- *   The fast vacuuming run has a short cut for those records
- *   that have never been migrated with data: these records
- *   are immediately deleted locally, since they have left
- *   no trace on other nodes.
- *
- * - The vacuum_fetch lists
- *   (one for each other lmaster node):
- *   The records in this list are sent for deletion to
- *   their lmaster in a bulk VACUUM_FETCH message.
- *
- *   The lmaster then migrates all these records to itelf
- *   so that they can be vacuumed there.
- *
- * This executes in the child context.
+ * Delete the records that we are lmaster and dmaster for and
+ * that could be deleted on all other nodes via the TRY_DELETE_RECORDS
+ * control.
  */
-static int ctdb_vacuum_db(struct ctdb_db_context *ctdb_db,
-                         struct vacuum_data *vdata,
-                         bool full_vacuum_run)
+static int delete_record_traverse(void *param, void *data)
 {
+       struct delete_record_data *dd =
+               talloc_get_type(data, struct delete_record_data);
+       struct vacuum_data *vdata = talloc_get_type(param, struct vacuum_data);
+       struct ctdb_db_context *ctdb_db = dd->ctdb_db;
        struct ctdb_context *ctdb = ctdb_db->ctdb;
-       const char *name = ctdb_db->db_name;
-       int ret, i, pnn;
+       int res;
+       struct ctdb_ltdb_header *header;
+       TDB_DATA tdb_data;
+       uint32_t lmaster;
+       bool deleted = false;
+       uint32_t hash = ctdb_hash(&(dd->key));
 
-       DEBUG(DEBUG_INFO, (__location__ " Entering %s vacuum run for db "
-                          "%s db_id[0x%08x]\n",
-                          full_vacuum_run ? "full" : "fast",
-                          ctdb_db->db_name, ctdb_db->db_id));
+       res = tdb_chainlock(ctdb_db->ltdb->tdb, dd->key);
+       if (res != 0) {
+               DEBUG(DEBUG_ERR,
+                     (__location__ " Error getting chainlock on record with "
+                      "key hash [0x%08x] on database db[%s].\n",
+                      hash, ctdb_db->db_name));
+               vdata->delete_local_error++;
+               return 0;
+       }
 
-       ret = ctdb_ctrl_getvnnmap(ctdb, TIMELIMIT(), CTDB_CURRENT_NODE, ctdb, &ctdb->vnn_map);
-       if (ret != 0) {
-               DEBUG(DEBUG_ERR, ("Unable to get vnnmap from local node\n"));
-               return ret;
+       /*
+        * Verify that the record is still empty, its RSN has not
+        * changed and that we are still its lmaster and dmaster.
+        */
+
+       tdb_data = tdb_fetch(ctdb_db->ltdb->tdb, dd->key);
+       if (tdb_data.dsize < sizeof(struct ctdb_ltdb_header)) {
+               DEBUG(DEBUG_INFO, (__location__ ": record with hash [0x%08x] "
+                                  "on database db[%s] does not exist or is not"
+                                  " a ctdb-record.  skipping.\n",
+                                  hash, ctdb_db->db_name));
+               vdata->delete_skipped++;
+               goto done;
        }
 
-       pnn = ctdb_ctrl_getpnn(ctdb, TIMELIMIT(), CTDB_CURRENT_NODE);
-       if (pnn == -1) {
-               DEBUG(DEBUG_ERR, ("Unable to get pnn from local node\n"));
-               return -1;
+       if (tdb_data.dsize > sizeof(struct ctdb_ltdb_header)) {
+               DEBUG(DEBUG_INFO, (__location__ ": record with hash [0x%08x] "
+                                  "on database db[%s] has been recycled. "
+                                  "skipping.\n",
+                                  hash, ctdb_db->db_name));
+               vdata->delete_skipped++;
+               goto done;
        }
 
-       ctdb->pnn = pnn;
+       header = (struct ctdb_ltdb_header *)tdb_data.dptr;
 
-       vdata->fast_added_to_delete_tree = 0;
-       vdata->fast_added_to_vacuum_fetch_list = 0;
-       vdata->fast_deleted = 0;
-       vdata->fast_skipped = 0;
-       vdata->fast_error = 0;
-       vdata->fast_total = 0;
-       vdata->full_added_to_delete_tree = 0;
-       vdata->full_added_to_vacuum_fetch_list = 0;
-       vdata->full_skipped = 0;
-       vdata->full_error = 0;
-       vdata->full_total = 0;
-       vdata->delete_count = 0;
+       if (header->dmaster != ctdb->pnn) {
+               DEBUG(DEBUG_INFO, (__location__ ": record with hash [0x%08x] "
+                                  "on database db[%s] has been migrated away. "
+                                  "skipping.\n",
+                                  hash, ctdb_db->db_name));
+               vdata->delete_skipped++;
+               goto done;
+       }
 
-       /* the list needs to be of length num_nodes */
-       vdata->list = talloc_array(vdata, struct ctdb_marshall_buffer *, ctdb->num_nodes);
-       if (vdata->list == NULL) {
-               DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
-               return -1;
+
+       if (header->rsn != dd->hdr.rsn) {
+               /*
+                * The record has been migrated off the node and back again.
+                * But not requeued for deletion. Skip it.
+                */
+               DEBUG(DEBUG_INFO, (__location__ ": record with hash [0x%08x] "
+                                  "on database db[%s] seems to have been "
+                                  "migrated away and back again (with empty "
+                                  "data). skipping.\n",
+                                  hash, ctdb_db->db_name));
+               vdata->delete_skipped++;
+               goto done;
        }
-       for (i = 0; i < ctdb->num_nodes; i++) {
-               vdata->list[i] = (struct ctdb_marshall_buffer *)
-                       talloc_zero_size(vdata->list,
-                                        offsetof(struct ctdb_marshall_buffer, data));
-               if (vdata->list[i] == NULL) {
-                       DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
-                       return -1;
-               }
-               vdata->list[i]->db_id = ctdb_db->db_id;
+
+       lmaster = ctdb_lmaster(ctdb_db->ctdb, &dd->key);
+
+       if (lmaster != ctdb->pnn) {
+               DEBUG(DEBUG_INFO, (__location__ ": not lmaster for record in "
+                                  "delete list (key hash [0x%08x], db[%s]). "
+                                  "Strange! skipping.\n",
+                                  hash, ctdb_db->db_name));
+               vdata->delete_skipped++;
+               goto done;
        }
 
-       /*
-        * Traverse the delete_queue.
-        * This builds the same lists as the db traverse.
-        */
+       res = tdb_delete(ctdb_db->ltdb->tdb, dd->key);
+
+       if (res != 0) {
+               DEBUG(DEBUG_ERR,
+                     (__location__ " Error deleting record with key hash "
+                      "[0x%08x] from local data base db[%s].\n",
+                      hash, ctdb_db->db_name));
+               vdata->delete_local_error++;
+               goto done;
+       }
+
+       deleted = true;
+
+       DEBUG(DEBUG_DEBUG,
+             (__location__ " Deleted record with key hash [0x%08x] from "
+              "local data base db[%s].\n", hash, ctdb_db->db_name));
+
+done:
+       if (tdb_data.dptr != NULL) {
+               free(tdb_data.dptr);
+       }
+
+       tdb_chainunlock(ctdb_db->ltdb->tdb, dd->key);
+
+       if (deleted) {
+               /*
+                * successfully deleted the record locally.
+                * remove it from the list and update statistics.
+                */
+               talloc_free(dd);
+               vdata->delete_deleted++;
+               vdata->delete_left--;
+       }
+
+       return 0;
+}
+
+/**
+ * Fast vacuuming run:
+ * Traverse the delete_queue.
+ * This fills the same lists as the database traverse.
+ */
+static void ctdb_vacuum_db_fast(struct ctdb_db_context *ctdb_db,
+                               struct vacuum_data *vdata)
+{
        trbt_traversearray32(ctdb_db->delete_queue, 1, delete_queue_traverse, vdata);
 
        if (vdata->fast_total > 0) {
@@ -530,192 +590,410 @@ static int ctdb_vacuum_db(struct ctdb_db_context *ctdb_db,
                       "del[%u] "
                       "skp[%u] "
                       "err[%u] "
-                      "adt[%u] "
+                      "adl[%u] "
                       "avf[%u]\n",
                       ctdb_db->db_name,
                       (unsigned)vdata->fast_total,
                       (unsigned)vdata->fast_deleted,
                       (unsigned)vdata->fast_skipped,
                       (unsigned)vdata->fast_error,
-                      (unsigned)vdata->fast_added_to_delete_tree,
+                      (unsigned)vdata->fast_added_to_delete_list,
                       (unsigned)vdata->fast_added_to_vacuum_fetch_list));
        }
 
-       /*
-        * read-only traverse of the database, looking for records that
-        * might be able to be vacuumed.
-        *
-        * This is not done each time but only every tunable
-        * VacuumFastPathCount times.
-        */
-       if (full_vacuum_run) {
-               ret = tdb_traverse_read(ctdb_db->ltdb->tdb, vacuum_traverse, vdata);
-               if (ret == -1 || vdata->traverse_error) {
-                       DEBUG(DEBUG_ERR,(__location__ " Traverse error in vacuuming '%s'\n", name));
-                       return -1;
-               }
-               if (vdata->full_total > 0) {
-                       DEBUG(DEBUG_INFO,
-                             (__location__
-                              " full vacuuming db traverse statistics: "
-                              "db[%s] "
-                              "total[%u] "
-                              "skp[%u] "
-                              "err[%u] "
-                              "adt[%u] "
-                              "avf[%u]\n",
-                              ctdb_db->db_name,
-                              (unsigned)vdata->full_total,
-                              (unsigned)vdata->full_skipped,
-                              (unsigned)vdata->full_error,
-                              (unsigned)vdata->full_added_to_delete_tree,
-                              (unsigned)vdata->full_added_to_vacuum_fetch_list));
-               }
+       return;
+}
+
+/**
+ * Full vacuum run:
+ * read-only traverse of the database, looking for records that
+ * might be able to be vacuumed.
+ *
+ * This is not done each time but only every tunable
+ * VacuumFastPathCount times.
+ */
+static int ctdb_vacuum_db_full(struct ctdb_db_context *ctdb_db,
+                              struct vacuum_data *vdata,
+                              bool full_vacuum_run)
+{
+       int ret;
+
+       if (!full_vacuum_run) {
+               return 0;
        }
 
-       /*
-        * For records where we are not the lmaster,
-        * tell the lmaster to fetch the record.
-        */
+       ret = tdb_traverse_read(ctdb_db->ltdb->tdb, vacuum_traverse, vdata);
+       if (ret == -1 || vdata->traverse_error) {
+               DEBUG(DEBUG_ERR, (__location__ " Traverse error in vacuuming "
+                                 "'%s'\n", ctdb_db->db_name));
+               return -1;
+       }
+
+       if (vdata->full_total > 0) {
+               DEBUG(DEBUG_INFO,
+                     (__location__
+                      " full vacuuming db traverse statistics: "
+                      "db[%s] "
+                      "total[%u] "
+                      "skp[%u] "
+                      "err[%u] "
+                      "adl[%u] "
+                      "avf[%u]\n",
+                      ctdb_db->db_name,
+                      (unsigned)vdata->full_total,
+                      (unsigned)vdata->full_skipped,
+                      (unsigned)vdata->full_error,
+                      (unsigned)vdata->full_added_to_delete_list,
+                      (unsigned)vdata->full_added_to_vacuum_fetch_list));
+       }
+
+       return 0;
+}
+
+/**
+ * Process the vacuum fetch lists:
+ * For records for which we are not the lmaster, tell the lmaster to
+ * fetch the record.
+ */
+static int ctdb_process_vacuum_fetch_lists(struct ctdb_db_context *ctdb_db,
+                                          struct vacuum_data *vdata)
+{
+       int i;
+       struct ctdb_context *ctdb = ctdb_db->ctdb;
+
        for (i = 0; i < ctdb->num_nodes; i++) {
                TDB_DATA data;
+               struct ctdb_marshall_buffer *vfl = vdata->vacuum_fetch_list[i];
 
                if (ctdb->nodes[i]->pnn == ctdb->pnn) {
                        continue;
                }
 
-               if (vdata->list[i]->count == 0) {
+               if (vfl->count == 0) {
                        continue;
                }
 
                DEBUG(DEBUG_INFO, ("Found %u records for lmaster %u in '%s'\n",
-                                  vdata->list[i]->count, ctdb->nodes[i]->pnn,
-                                  name));
-
-               data.dsize = talloc_get_size(vdata->list[i]);
-               data.dptr  = (void *)vdata->list[i];
-               if (ctdb_send_message(ctdb, ctdb->nodes[i]->pnn, CTDB_SRVID_VACUUM_FETCH, data) != 0) {
+                                  vfl->count, ctdb->nodes[i]->pnn,
+                                  ctdb_db->db_name));
+
+               data.dsize = talloc_get_size(vfl);
+               data.dptr  = (void *)vfl;
+               if (ctdb_send_message(ctdb, ctdb->nodes[i]->pnn,
+                                     CTDB_SRVID_VACUUM_FETCH,
+                                     data) != 0)
+               {
                        DEBUG(DEBUG_ERR, (__location__ " Failed to send vacuum "
                                          "fetch message to %u\n",
                                          ctdb->nodes[i]->pnn));
                        return -1;
                }
-       }       
+       }
 
-       /* Process all records we can delete (if any) */
-       if (vdata->delete_count > 0) {
-               struct delete_records_list *recs;
-               TDB_DATA indata, outdata;
+       return 0;
+}
+
+/**
+ * Process the delete list:
+ * Send the records to delete to all other nodes with the
+ * try_delete_records control.
+ */
+static int ctdb_process_delete_list(struct ctdb_db_context *ctdb_db,
+                                   struct vacuum_data *vdata)
+{
+       int ret, i;
+       struct ctdb_context *ctdb = ctdb_db->ctdb;
+       struct delete_records_list *recs;
+       TDB_DATA indata, outdata;
+       struct ctdb_node_map *nodemap;
+       uint32_t *active_nodes;
+       int num_active_nodes;
+
+       if (vdata->delete_count == 0) {
+               return 0;
+       }
+
+       vdata->delete_left = vdata->delete_count;
+
+       recs = talloc_zero(vdata, struct delete_records_list);
+       if (recs == NULL) {
+               DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
+               return -1;
+       }
+       recs->records = (struct ctdb_marshall_buffer *)
+               talloc_zero_size(vdata,
+                           offsetof(struct ctdb_marshall_buffer, data));
+       if (recs->records == NULL) {
+               DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
+               return -1;
+       }
+       recs->records->db_id = ctdb_db->db_id;
+
+       /*
+        * traverse the tree of all records we want to delete and
+        * create a blob we can send to the other nodes.
+        */
+       trbt_traversearray32(vdata->delete_list, 1,
+                            delete_marshall_traverse, recs);
+
+       indata.dsize = talloc_get_size(recs->records);
+       indata.dptr  = (void *)recs->records;
+
+       /*
+        * now tell all the active nodes to delete all these records
+        * (if possible)
+        */
+
+       ret = ctdb_ctrl_getnodemap(ctdb, TIMELIMIT(),
+                                  CTDB_CURRENT_NODE,
+                                  recs, /* talloc context */
+                                  &nodemap);
+       if (ret != 0) {
+               DEBUG(DEBUG_ERR,(__location__ " unable to get node map\n"));
+               return -1;
+       }
+
+       active_nodes = list_of_active_nodes(ctdb, nodemap,
+                                           nodemap, /* talloc context */
+                                           false /* include self */);
+       /* yuck! ;-) */
+       num_active_nodes = talloc_get_size(active_nodes)/sizeof(*active_nodes);
+
+       for (i = 0; i < num_active_nodes; i++) {
+               struct ctdb_marshall_buffer *records;
+               struct ctdb_rec_data *rec;
                int32_t res;
-               struct ctdb_node_map *nodemap;
-               uint32_t *active_nodes;
-               int num_active_nodes;
 
-               recs = talloc_zero(vdata, struct delete_records_list);
-               if (recs == NULL) {
-                       DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
+               ret = ctdb_control(ctdb, active_nodes[i], 0,
+                               CTDB_CONTROL_TRY_DELETE_RECORDS, 0,
+                               indata, recs, &outdata, &res,
+                               NULL, NULL);
+               if (ret != 0 || res != 0) {
+                       DEBUG(DEBUG_ERR, ("Failed to delete records on "
+                                         "node %u: ret[%d] res[%d]\n",
+                                         active_nodes[i], ret, res));
                        return -1;
                }
-               recs->records = (struct ctdb_marshall_buffer *)
-                       talloc_zero_size(vdata, 
-                                   offsetof(struct ctdb_marshall_buffer, data));
-               if (recs->records == NULL) {
-                       DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
-                       return -1;
-               }
-               recs->records->db_id = ctdb_db->db_id;
 
-               /* 
-                * traverse the tree of all records we want to delete and
-                * create a blob we can send to the other nodes.
+               /*
+                * outdata contains the list of records coming back
+                * from the node: These are the records that the
+                * remote node could not delete.
+                *
+                * NOTE: There is a problem here:
+                *
+                * When a node failed to delete the record, but
+                * others succeeded, we may have created gaps in the
+                * history of the record. Hence when a node dies, an
+                * closed file handle might be resurrected or an open
+                * file handle might be lost, leading to blocked access
+                * or data corruption.
+                *
+                * TODO: This needs to be fixed!
                 */
-               trbt_traversearray32(vdata->delete_tree, 1,
-                                    delete_marshall_traverse, recs);
+               records = (struct ctdb_marshall_buffer *)outdata.dptr;
+               rec = (struct ctdb_rec_data *)&records->data[0];
+               while (records->count-- > 1) {
+                       TDB_DATA reckey, recdata;
+                       struct ctdb_ltdb_header *rechdr;
+                       struct delete_record_data *dd;
+
+                       reckey.dptr = &rec->data[0];
+                       reckey.dsize = rec->keylen;
+                       recdata.dptr = &rec->data[reckey.dsize];
+                       recdata.dsize = rec->datalen;
+
+                       if (recdata.dsize < sizeof(struct ctdb_ltdb_header)) {
+                               DEBUG(DEBUG_CRIT,(__location__ " bad ltdb record\n"));
+                               return -1;
+                       }
+                       rechdr = (struct ctdb_ltdb_header *)recdata.dptr;
+                       recdata.dptr += sizeof(*rechdr);
+                       recdata.dsize -= sizeof(*rechdr);
+
+                       dd = (struct delete_record_data *)trbt_lookup32(
+                                       vdata->delete_list,
+                                       (uint32_t)tdb_jenkins_hash(&reckey));
+                       if (dd != NULL) {
+                               /*
+                                * The other node could not delete the
+                                * record and it is the first node that
+                                * failed. So we should remove it from
+                                * the tree and update statistics.
+                                */
+                               talloc_free(dd);
+                               vdata->delete_remote_error++;
+                               vdata->delete_left--;
+                       }
 
-               indata.dsize = talloc_get_size(recs->records);
-               indata.dptr  = (void *)recs->records;
+                       rec = (struct ctdb_rec_data *)(rec->length + (uint8_t *)rec);
+               }
+       }
 
-               /* 
-                * now tell all the active nodes to delete all these records
-                * (if possible)
+       /* free nodemap and active_nodes */
+       talloc_free(nodemap);
+
+       if (vdata->delete_left > 0) {
+               /*
+                * The only records remaining in the tree are those
+                * records which all other nodes could successfully
+                * delete, so we can safely delete them on the
+                * lmaster as well.
                 */
+               trbt_traversearray32(vdata->delete_list, 1,
+                                    delete_record_traverse, vdata);
+       }
+
+       if (vdata->delete_count > 0) {
+               DEBUG(DEBUG_INFO,
+                     (__location__
+                      " vacuum delete list statistics: "
+                      "db[%s] "
+                      "coll[%u] "
+                      "rem.err[%u] "
+                      "loc.err[%u] "
+                      "skip[%u] "
+                      "del[%u] "
+                      "left[%u]\n",
+                      ctdb_db->db_name,
+                      (unsigned)vdata->delete_count,
+                      (unsigned)vdata->delete_remote_error,
+                      (unsigned)vdata->delete_local_error,
+                      (unsigned)vdata->delete_skipped,
+                      (unsigned)vdata->delete_deleted,
+                      (unsigned)vdata->delete_left));
+       }
 
-               ret = ctdb_ctrl_getnodemap(ctdb, TIMELIMIT(),
-                                          CTDB_CURRENT_NODE,
-                                          recs, /* talloc context */
-                                          &nodemap);
-               if (ret != 0) {
-                       DEBUG(DEBUG_ERR,(__location__ " unable to get node map\n"));
+       return 0;
+}
+
+/**
+ * initialize the vacuum_data
+ */
+static int ctdb_vacuum_init_vacuum_data(struct ctdb_db_context *ctdb_db,
+                                       struct vacuum_data *vdata)
+{
+       int i;
+       struct ctdb_context *ctdb = ctdb_db->ctdb;
+
+       vdata->fast_added_to_delete_list = 0;
+       vdata->fast_added_to_vacuum_fetch_list = 0;
+       vdata->fast_deleted = 0;
+       vdata->fast_skipped = 0;
+       vdata->fast_error = 0;
+       vdata->fast_total = 0;
+       vdata->full_added_to_delete_list = 0;
+       vdata->full_added_to_vacuum_fetch_list = 0;
+       vdata->full_skipped = 0;
+       vdata->full_error = 0;
+       vdata->full_total = 0;
+       vdata->delete_count = 0;
+       vdata->delete_left = 0;
+       vdata->delete_remote_error = 0;
+       vdata->delete_local_error = 0;
+       vdata->delete_skipped = 0;
+       vdata->delete_deleted = 0;
+
+       /* the list needs to be of length num_nodes */
+       vdata->vacuum_fetch_list = talloc_zero_array(vdata,
+                                               struct ctdb_marshall_buffer *,
+                                               ctdb->num_nodes);
+       if (vdata->vacuum_fetch_list == NULL) {
+               DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
+               return -1;
+       }
+       for (i = 0; i < ctdb->num_nodes; i++) {
+               vdata->vacuum_fetch_list[i] = (struct ctdb_marshall_buffer *)
+                       talloc_zero_size(vdata->vacuum_fetch_list,
+                                        offsetof(struct ctdb_marshall_buffer, data));
+               if (vdata->vacuum_fetch_list[i] == NULL) {
+                       DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
                        return -1;
                }
+               vdata->vacuum_fetch_list[i]->db_id = ctdb_db->db_id;
+       }
 
-               active_nodes = list_of_active_nodes(ctdb, nodemap,
-                                                   nodemap, /* talloc context */
-                                                   false /* include self */);
-               /* yuck! ;-) */
-               num_active_nodes = talloc_get_size(active_nodes)/sizeof(*active_nodes);
-
-               for (i = 0; i < num_active_nodes; i++) {
-                       struct ctdb_marshall_buffer *records;
-                       struct ctdb_rec_data *rec;
-
-                       ret = ctdb_control(ctdb, active_nodes[i], 0,
-                                       CTDB_CONTROL_TRY_DELETE_RECORDS, 0,
-                                       indata, recs, &outdata, &res,
-                                       NULL, NULL);
-                       if (ret != 0 || res != 0) {
-                               DEBUG(DEBUG_ERR, ("Failed to delete records on "
-                                                 "node %u: ret[%d] res[%d]\n",
-                                                 active_nodes[i], ret, res));
-                               return -1;
-                       }
+       return 0;
+}
 
-                       /* 
-                        * outdata countains the list of records coming back
-                        * from the node which the node could not delete
-                        */
-                       records = (struct ctdb_marshall_buffer *)outdata.dptr;
-                       rec = (struct ctdb_rec_data *)&records->data[0];
-                       while (records->count-- > 1) {
-                               TDB_DATA reckey, recdata;
-                               struct ctdb_ltdb_header *rechdr;
-
-                               reckey.dptr = &rec->data[0];
-                               reckey.dsize = rec->keylen;
-                               recdata.dptr = &rec->data[reckey.dsize];
-                               recdata.dsize = rec->datalen;
-
-                               if (recdata.dsize < sizeof(struct ctdb_ltdb_header)) {
-                                       DEBUG(DEBUG_CRIT,(__location__ " bad ltdb record\n"));
-                                       return -1;
-                               }
-                               rechdr = (struct ctdb_ltdb_header *)recdata.dptr;
-                               recdata.dptr += sizeof(*rechdr);
-                               recdata.dsize -= sizeof(*rechdr);
-
-                               /* 
-                                * that other node couldnt delete the record
-                                * so we should delete it and thereby remove it from the tree
-                                */
-                               talloc_free(trbt_lookup32(vdata->delete_tree,
-                                                         (uint32_t)tdb_jenkins_hash(&reckey)));
+/**
+ * Vacuum a DB:
+ *  - Always do the fast vacuuming run, which traverses
+ *    the in-memory delete queue: these records have been
+ *    scheduled for deletion.
+ *  - Only if explicitly requested, the database is traversed
+ *    in order to use the traditional heuristics on empty records
+ *    to trigger deletion.
+ *    This is done only every VacuumFastPathCount'th vacuuming run.
+ *
+ * The traverse runs fill two lists:
+ *
+ * - The delete_list:
+ *   This is the list of empty records the current
+ *   node is lmaster and dmaster for. These records are later
+ *   deleted first on other nodes and then locally.
+ *
+ *   The fast vacuuming run has a short cut for those records
+ *   that have never been migrated with data: these records
+ *   are immediately deleted locally, since they have left
+ *   no trace on other nodes.
+ *
+ * - The vacuum_fetch lists
+ *   (one for each other lmaster node):
+ *   The records in this list are sent for deletion to
+ *   their lmaster in a bulk VACUUM_FETCH message.
+ *
+ *   The lmaster then migrates all these records to itelf
+ *   so that they can be vacuumed there.
+ *
+ * This executes in the child context.
+ */
+static int ctdb_vacuum_db(struct ctdb_db_context *ctdb_db,
+                         struct vacuum_data *vdata,
+                         bool full_vacuum_run)
+{
+       struct ctdb_context *ctdb = ctdb_db->ctdb;
+       int ret, pnn;
 
-                               rec = (struct ctdb_rec_data *)(rec->length + (uint8_t *)rec);
-                       }           
-               }
+       DEBUG(DEBUG_INFO, (__location__ " Entering %s vacuum run for db "
+                          "%s db_id[0x%08x]\n",
+                          full_vacuum_run ? "full" : "fast",
+                          ctdb_db->db_name, ctdb_db->db_id));
 
-               /* free nodemap and active_nodes */
-               talloc_free(nodemap);
+       ret = ctdb_ctrl_getvnnmap(ctdb, TIMELIMIT(), CTDB_CURRENT_NODE, ctdb, &ctdb->vnn_map);
+       if (ret != 0) {
+               DEBUG(DEBUG_ERR, ("Unable to get vnnmap from local node\n"));
+               return ret;
+       }
 
-               /* 
-                * The only records remaining in the tree would be those
-                * records where all other nodes could successfully
-                * delete them, so we can safely delete them on the
-                * lmaster as well. Deletion implictely happens while
-                * we repack the database. The repack algorithm revisits 
-                * the tree in order to find the records that don't need
-                * to be copied / repacked.
-                */
+       pnn = ctdb_ctrl_getpnn(ctdb, TIMELIMIT(), CTDB_CURRENT_NODE);
+       if (pnn == -1) {
+               DEBUG(DEBUG_ERR, ("Unable to get pnn from local node\n"));
+               return -1;
+       }
+
+       ctdb->pnn = pnn;
+
+       ret = ctdb_vacuum_init_vacuum_data(ctdb_db, vdata);
+       if (ret != 0) {
+               return ret;
+       }
+
+       ctdb_vacuum_db_fast(ctdb_db, vdata);
+
+       ret = ctdb_vacuum_db_full(ctdb_db, vdata, full_vacuum_run);
+       if (ret != 0) {
+               return ret;
+       }
+
+       ret = ctdb_process_vacuum_fetch_lists(ctdb_db, vdata);
+       if (ret != 0) {
+               return ret;
+       }
+
+       ret = ctdb_process_delete_list(ctdb_db, vdata);
+       if (ret != 0) {
+               return ret;
        }
 
        /* this ensures we run our event queue */
@@ -736,9 +1014,9 @@ static int repack_traverse(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data,
                uint32_t hash = (uint32_t)tdb_jenkins_hash(&key);
                struct delete_record_data *kd;
                /*
-                * check if we can ignore this record because it's in the delete_tree
+                * check if we can ignore this record because it's in the delete_list
                 */
-               kd = (struct delete_record_data *)trbt_lookup32(vdata->delete_tree, hash);
+               kd = (struct delete_record_data *)trbt_lookup32(vdata->delete_list, hash);
                /*
                 * there might be hash collisions so we have to compare the keys here to be sure
                 */
@@ -879,9 +1157,9 @@ static int ctdb_vacuum_and_repack_db(struct ctdb_db_context *ctdb_db,
        vdata->ctdb = ctdb_db->ctdb;
        vdata->vacuum_limit = vacuum_limit;
        vdata->repack_limit = repack_limit;
-       vdata->delete_tree = trbt_create(vdata, 0);
+       vdata->delete_list = trbt_create(vdata, 0);
        vdata->ctdb_db = ctdb_db;
-       if (vdata->delete_tree == NULL) {
+       if (vdata->delete_list == NULL) {
                DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
                talloc_free(vdata);
                return -1;
@@ -899,14 +1177,14 @@ static int ctdb_vacuum_and_repack_db(struct ctdb_db_context *ctdb_db,
        /*
         * decide if a repack is necessary
         */
-       if (freelist_size < repack_limit && vdata->delete_count < vacuum_limit)
+       if (freelist_size < repack_limit && vdata->delete_left < vacuum_limit)
        {
                talloc_free(vdata);
                return 0;
        }
 
        DEBUG(DEBUG_INFO,("Repacking %s with %u freelist entries and %u records to delete\n", 
-                       name, freelist_size, vdata->delete_count));
+                       name, freelist_size, vdata->delete_left));
 
        /*
         * repack and implicitely get rid of the records we can delete
@@ -1160,7 +1438,8 @@ static void remove_record_from_delete_queue(struct ctdb_db_context *ctdb_db,
        hash = (uint32_t)tdb_jenkins_hash(discard_const(&key));
 
        DEBUG(DEBUG_DEBUG, (__location__
-                           " remove_record_from_delete_queue: db[%s] "
+                           " remove_record_from_delete_queue: "
+                           "db[%s] "
                            "db_id[0x%08x] "
                            "key_hash[0x%08x] "
                            "lmaster[%u] "
@@ -1172,15 +1451,29 @@ static void remove_record_from_delete_queue(struct ctdb_db_context *ctdb_db,
 
        kd = (struct delete_record_data *)trbt_lookup32(ctdb_db->delete_queue, hash);
        if (kd == NULL) {
+               DEBUG(DEBUG_DEBUG, (__location__
+                                   " remove_record_from_delete_queue: "
+                                   "record not in queue (hash[0x%08x])\n.",
+                                   hash));
                return;
        }
-       if (kd->key.dsize != key.dsize) {
-               return;
-       }
-       if (memcmp(kd->key.dptr, key.dptr, key.dsize) != 0) {
+
+       if ((kd->key.dsize != key.dsize) ||
+           (memcmp(kd->key.dptr, key.dptr, key.dsize) != 0))
+       {
+               DEBUG(DEBUG_DEBUG, (__location__
+                                   " remove_record_from_delete_queue: "
+                                   "hash collision for key with hash[0x%08x] "
+                                   "in db[%s] - skipping\n",
+                                   hash, ctdb_db->db_name));
                return;
        }
 
+       DEBUG(DEBUG_DEBUG, (__location__
+                           " remove_record_from_delete_queue: "
+                           "removing key with hash[0x%08x]\n",
+                            hash));
+
        talloc_free(kd);
 
        return;
@@ -1200,7 +1493,7 @@ static int insert_record_into_delete_queue(struct ctdb_db_context *ctdb_db,
 
        hash = (uint32_t)tdb_jenkins_hash(&key);
 
-       DEBUG(DEBUG_INFO, (__location__ " Schedule for deletion: db[%s] "
+       DEBUG(DEBUG_INFO, (__location__ " schedule for deletion: db[%s] "
                           "db_id[0x%08x] "
                           "key_hash[0x%08x] "
                           "lmaster[%u] "
@@ -1216,13 +1509,15 @@ static int insert_record_into_delete_queue(struct ctdb_db_context *ctdb_db,
                    (memcmp(kd->key.dptr, key.dptr, key.dsize) != 0))
                {
                        DEBUG(DEBUG_INFO,
-                             ("schedule for deletion: Hash collision (0x%08x)."
-                              " Skipping the record.\n", hash));
+                             (__location__ " schedule for deletion: "
+                              "hash collision for key hash [0x%08x]. "
+                              "Skipping the record.\n", hash));
                        return 0;
                } else {
                        DEBUG(DEBUG_DEBUG,
-                             ("schedule for deletion: Overwriting entry for "
-                              "key with hash 0x%08x.\n", hash));
+                             (__location__ " schedule for deletion: "
+                              "updating entry for key with hash [0x%08x].\n",
+                              hash));
                }
        }
 
@@ -1230,6 +1525,10 @@ static int insert_record_into_delete_queue(struct ctdb_db_context *ctdb_db,
                                                  ctdb_db->delete_queue,
                                                  hdr, key);
        if (ret != 0) {
+               DEBUG(DEBUG_INFO,
+                     (__location__ " schedule for deletion: error "
+                      "inserting key with hash [0x%08x] into delete queue\n",
+                      hash));
                return -1;
        }