cluster/tier: handle fast demotions

Demote files on priority if hi-watermark has been breached and continue
to demote until the watermark drops below hi-watermark.

Monitor watermark more frequently.
Trigger demotion as soon as hi-watermark is breached.
Add cluster.tier-emergency-demote-query-limit option to limit number
of files returned from the database query for every iteration of
tier_migrate_using_query_file(). If watermark hasn't dropped below
hi-watermark during the first iteration, the next iteration will be
triggered approximately 1 second after tier_demote() returns to the
main tiering loop.
Update changetimerecorder xlator to handle query for emergency demote
mode.

Add tier-ctr-interface.h:
Move tier and ctr interface specific macros and struct definition from
libglusterfs/src/gfdb/gfdb_data_store.h to new header
libglusterfs/src/tier-ctr-interface.h

Change-Id: If56af78c6c81d37529b9b6e65ae606ba5c99a811
BUG: 1366648
Signed-off-by: Milind Changire <mchangir@redhat.com>
Reviewed-on: http://review.gluster.org/15158
Smoke: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>

1 files changed, 11 insertions, 37 deletions

diff --git a/libglusterfs/src/gfdb/gfdb_data_store.h b/libglusterfs/src/gfdb/gfdb_data_store.h
index 0aac4611153..beb954c190a 100644
--- a/libglusterfs/src/gfdb/gfdb_data_store.h
+++ b/libglusterfs/src/gfdb/gfdb_data_store.h
@@ -20,42 +20,6 @@
 
 #include "gfdb_data_store_types.h"
 
-#define GFDB_IPC_CTR_KEY "gfdb.ipc-ctr-op"
-
-/*
- * CTR IPC OPERATIONS
- *
- *
- */
-#define GFDB_IPC_CTR_QUERY_OPS "gfdb.ipc-ctr-query-op"
-#define GFDB_IPC_CTR_CLEAR_OPS "gfdb.ipc-ctr-clear-op"
-#define GFDB_IPC_CTR_GET_DB_PARAM_OPS "gfdb.ipc-ctr-get-db-parm"
-#define GFDB_IPC_CTR_GET_DB_VERSION_OPS "gfdb.ipc-ctr-get-db-version"
-#define GFDB_IPC_CTR_SET_COMPACT_PRAGMA "gfdb.ipc-ctr-set-compact-pragma"
-/*
- * CTR IPC INPUT/OUTPUT
- *
- *
- */
-#define GFDB_IPC_CTR_GET_QFILE_PATH "gfdb.ipc-ctr-get-qfile-path"
-#define GFDB_IPC_CTR_GET_QUERY_PARAMS "gfdb.ipc-ctr-get-query-parms"
-#define GFDB_IPC_CTR_RET_QUERY_COUNT "gfdb.ipc-ctr-ret-rec-count"
-#define GFDB_IPC_CTR_GET_DB_KEY "gfdb.ipc-ctr-get-params-key"
-#define GFDB_IPC_CTR_RET_DB_VERSION "gfdb.ipc-ctr-ret-db-version"
-
-/*
- * gfdb ipc ctr params for query
- *
- *
- */
-typedef struct gfdb_ipc_ctr_params {
-        gf_boolean_t is_promote;
-        int write_freq_threshold;
-        int read_freq_threshold;
-        gfdb_time_t time_stamp;
-} gfdb_ipc_ctr_params_t;
-
-
 /* GFDB Connection Node:
  * ~~~~~~~~~~~~~~~~~~~~
  * Represents the connection to the database while using libgfdb
@@ -146,11 +110,20 @@ delete_record(gfdb_conn_node_t *, gfdb_db_record_t *gfdb_db_record);
  *                        for every record found
  *      _query_cbk_args : Custom argument passed for the call back
  *                        function query_callback
+ *      query_limit     : 0 - umlimited,
+ *                        any positive value - adds the LIMIT clause
+ *                        to the SQL query
+ *
  * Returns : if successful return 0 or
  *          -ve value in case of failure*/
 int find_all(gfdb_conn_node_t *, gf_query_callback_t query_callback,
-                void *_query_cbk_args);
+                void *_query_cbk_args,
+                int query_limit);
 
+typedef int (*find_all_t) (gfdb_conn_node_t *,
+                           gf_query_callback_t query_callback,
+                           void *_query_cbk_args,
+                           int query_limit);
 
 
 
@@ -368,6 +341,7 @@ typedef int (*compact_db_t)(gfdb_conn_node_t *db_conn,
 typedef struct gfdb_methods_s {
         init_db_t                       init_db;
         fini_db_t                       fini_db;
+        find_all_t                      find_all;
         find_unchanged_for_time_t       find_unchanged_for_time;
         find_recently_changed_files_t   find_recently_changed_files;
         find_unchanged_for_time_freq_t  find_unchanged_for_time_freq;