From 41ff8fd5aabda7d180d6c9458f43eb436ebcf947 Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Mon, 29 Nov 2010 13:07:59 +1100 Subject: [PATCH] Remove LACOUNT and LACCESSOR and migrate the records immediately. This concept didnt work out and it is really just as expensive as a full migration anyway, without the benefit of caching the data for subsequence accesses. Now, migrate the records immediately on first access. This will be combined with a "cheap vacuum-lite" for special empty records to prevent growth of databases. Later extensions to mimic read-only behaviour of records will include proper shared read-only locking of database records, making the laccessor/lacount read-only access to the data obsolete anyway. By removing this special case and handling of lacount laccessor makes the codapath where shared read-only locking will be be implemented simpler, and frees up space in the ctdb_ltdb header for use by vacuuming flags as well as read-only locking flags. --- client/ctdb_client.c | 15 ++++----------- common/ctdb_ltdb.c | 1 - include/ctdb_client.h | 5 ----- include/ctdb_private.h | 5 ++--- include/ctdb_protocol.h | 4 ++-- server/ctdb_call.c | 19 ++++++++----------- server/ctdb_tunables.c | 1 - 7 files changed, 16 insertions(+), 34 deletions(-) diff --git a/client/ctdb_client.c b/client/ctdb_client.c index 4c770fda..1abea127 100644 --- a/client/ctdb_client.c +++ b/client/ctdb_client.c @@ -72,7 +72,7 @@ struct ctdb_req_header *_ctdbd_allocate_pkt(struct ctdb_context *ctdb, */ int ctdb_call_local(struct ctdb_db_context *ctdb_db, struct ctdb_call *call, struct ctdb_ltdb_header *header, TALLOC_CTX *mem_ctx, - TDB_DATA *data, uint32_t caller) + TDB_DATA *data) { struct ctdb_call_info *c; struct ctdb_registered_call *fn; @@ -105,15 +105,8 @@ int ctdb_call_local(struct ctdb_db_context *ctdb_db, struct ctdb_call *call, return -1; } - if (header->laccessor != caller) { - header->lacount = 0; - } - header->laccessor = caller; - header->lacount++; - - /* we need to force the record to be written out if this was a remote access, - so that the lacount is updated */ - if (c->new_data == NULL && header->laccessor != ctdb->pnn) { + /* we need to force the record to be written out if this was a remote access */ + if (c->new_data == NULL) { c->new_data = &c->record_data; } @@ -368,7 +361,7 @@ static struct ctdb_client_call_state *ctdb_client_call_local_send(struct ctdb_db *(state->call) = *call; state->ctdb_db = ctdb_db; - ret = ctdb_call_local(ctdb_db, state->call, header, state, data, ctdb->pnn); + ret = ctdb_call_local(ctdb_db, state->call, header, state, data); return state; } diff --git a/common/ctdb_ltdb.c b/common/ctdb_ltdb.c index 7dc28ddf..c9693e83 100644 --- a/common/ctdb_ltdb.c +++ b/common/ctdb_ltdb.c @@ -65,7 +65,6 @@ static void ltdb_initial_header(struct ctdb_db_context *ctdb_db, ZERO_STRUCTP(header); /* initial dmaster is the lmaster */ header->dmaster = ctdb_lmaster(ctdb_db->ctdb, &key); - header->laccessor = header->dmaster; } diff --git a/include/ctdb_client.h b/include/ctdb_client.h index aa9b2c08..3dc115f0 100644 --- a/include/ctdb_client.h +++ b/include/ctdb_client.h @@ -76,11 +76,6 @@ int ctdb_set_tdb_dir_state(struct ctdb_context *ctdb, const char *dir); */ void ctdb_set_flags(struct ctdb_context *ctdb, unsigned flags); -/* - set max acess count before a dmaster migration -*/ -void ctdb_set_max_lacount(struct ctdb_context *ctdb, unsigned count); - /* tell ctdb what address to listen on, in transport specific format */ diff --git a/include/ctdb_private.h b/include/ctdb_private.h index 2d384a48..0df5ca5a 100644 --- a/include/ctdb_private.h +++ b/include/ctdb_private.h @@ -82,7 +82,6 @@ struct ctdb_tunable { uint32_t traverse_timeout; uint32_t keepalive_interval; uint32_t keepalive_limit; - uint32_t max_lacount; uint32_t recover_timeout; uint32_t recover_interval; uint32_t election_timeout; @@ -770,8 +769,8 @@ struct ctdb_call_state *ctdb_daemon_call_send_remote(struct ctdb_db_context *ctd struct ctdb_ltdb_header *header); int ctdb_call_local(struct ctdb_db_context *ctdb_db, struct ctdb_call *call, - struct ctdb_ltdb_header *header, TALLOC_CTX *mem_ctx, TDB_DATA *data, - uint32_t caller); + struct ctdb_ltdb_header *header, TALLOC_CTX *mem_ctx, + TDB_DATA *data); #define ctdb_reqid_find(ctdb, reqid, type) (type *)_ctdb_reqid_find(ctdb, reqid, #type, __location__) diff --git a/include/ctdb_protocol.h b/include/ctdb_protocol.h index 1568460a..12e4c89b 100644 --- a/include/ctdb_protocol.h +++ b/include/ctdb_protocol.h @@ -476,8 +476,8 @@ enum ctdb_trans2_commit_error { struct ctdb_ltdb_header { uint64_t rsn; uint32_t dmaster; - uint32_t laccessor; - uint32_t lacount; + uint32_t reserved1; + uint32_t reserved2; }; diff --git a/server/ctdb_call.c b/server/ctdb_call.c index c5f7e7d4..d6c08666 100644 --- a/server/ctdb_call.c +++ b/server/ctdb_call.c @@ -297,7 +297,7 @@ static void ctdb_become_dmaster(struct ctdb_db_context *ctdb_db, return; } - ctdb_call_local(ctdb_db, state->call, &header, state, &data, ctdb->pnn); + ctdb_call_local(ctdb_db, state->call, &header, state, &data); ret = ctdb_ltdb_unlock(ctdb_db, state->call->key); if (ret != 0) { @@ -465,14 +465,11 @@ void ctdb_request_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr) CTDB_UPDATE_STAT(ctdb, max_hop_count, c->hopcount); - /* if this nodes has done enough consecutive calls on the same record - then give them the record - or if the node requested an immediate migration - */ - if ( c->hdr.srcnode != ctdb->pnn && - ((header.laccessor == c->hdr.srcnode - && header.lacount >= ctdb->tunable.max_lacount) - || (c->flags & CTDB_IMMEDIATE_MIGRATION)) ) { + /* Try if possible to migrate the record off to the caller node. + * From the clients perspective a fetch of the data is just as + * expensive as a migration. + */ + if (c->hdr.srcnode != ctdb->pnn) { if (ctdb_db->transaction_active) { DEBUG(DEBUG_INFO, (__location__ " refusing migration" " of key %s while transaction is active\n", @@ -491,7 +488,7 @@ void ctdb_request_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr) } } - ctdb_call_local(ctdb_db, call, &header, hdr, &data, c->hdr.srcnode); + ctdb_call_local(ctdb_db, call, &header, hdr, &data); ret = ctdb_ltdb_unlock(ctdb_db, call->key); if (ret != 0) { @@ -707,7 +704,7 @@ struct ctdb_call_state *ctdb_call_local_send(struct ctdb_db_context *ctdb_db, *(state->call) = *call; state->ctdb_db = ctdb_db; - ret = ctdb_call_local(ctdb_db, state->call, header, state, data, ctdb->pnn); + ret = ctdb_call_local(ctdb_db, state->call, header, state, data); event_add_timed(ctdb->ev, state, timeval_zero(), call_local_trigger, state); diff --git a/server/ctdb_tunables.c b/server/ctdb_tunables.c index 47694b7e..4cd1b457 100644 --- a/server/ctdb_tunables.c +++ b/server/ctdb_tunables.c @@ -30,7 +30,6 @@ static const struct { { "TraverseTimeout", 20, offsetof(struct ctdb_tunable, traverse_timeout) }, { "KeepaliveInterval", 5, offsetof(struct ctdb_tunable, keepalive_interval) }, { "KeepaliveLimit", 5, offsetof(struct ctdb_tunable, keepalive_limit) }, - { "MaxLACount", 7, offsetof(struct ctdb_tunable, max_lacount) }, { "RecoverTimeout", 20, offsetof(struct ctdb_tunable, recover_timeout) }, { "RecoverInterval", 1, offsetof(struct ctdb_tunable, recover_interval) }, { "ElectionTimeout", 3, offsetof(struct ctdb_tunable, election_timeout) }, -- 2.34.1