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>

7 files changed, 102 insertions, 49 deletions

diff --git a/libglusterfs/src/Makefile.am b/libglusterfs/src/Makefile.am
index 20163da769c..e9e690ee4bd 100644
--- a/libglusterfs/src/Makefile.am
+++ b/libglusterfs/src/Makefile.am
@@ -61,7 +61,8 @@ noinst_HEADERS = unittest/unittest.h \
 	$(CONTRIBDIR)/rbtree/rb.h \
 	$(CONTRIBDIR)/mount/mntent_compat.h \
 	$(CONTRIBDIR)/libexecinfo/execinfo_compat.h \
-	$(CONTRIBDIR)/timer-wheel/timer-wheel.h
+	$(CONTRIBDIR)/timer-wheel/timer-wheel.h \
+	tier-ctr-interface.h
 
 if !HAVE_LIBUUID
 # FIXME: unbundle libuuid, see compat-uuid.h.
diff --git a/libglusterfs/src/gfdb/gfdb_data_store.c b/libglusterfs/src/gfdb/gfdb_data_store.c
index cb567503fa3..7074c4a51c2 100644
--- a/libglusterfs/src/gfdb/gfdb_data_store.c
+++ b/libglusterfs/src/gfdb/gfdb_data_store.c
@@ -481,12 +481,14 @@ compact_db (gfdb_conn_node_t *_conn_node, gf_boolean_t _compact_active,
  *                        for every record found
  *      _query_cbk_args : Custom argument passed for the call back
  *                        function query_callback
+ *      query_limit     : number to limit number of rows returned by the query
  * Returns : if successful return 0 or
  *          -ve value in case of failure*/
 int
 find_all (gfdb_conn_node_t      *_conn_node,
           gf_query_callback_t   query_callback,
-          void                  *_query_cbk_args)
+          void                  *_query_cbk_args,
+          int                   query_limit)
 {
         int ret                                 = 0;
         gfdb_db_operations_t *db_operations_t   = NULL;
@@ -500,7 +502,8 @@ find_all (gfdb_conn_node_t      *_conn_node,
         if (db_operations_t->find_all_op) {
                 ret = db_operations_t->find_all_op (gf_db_connection,
                                                     query_callback,
-                                                    _query_cbk_args);
+                                                    _query_cbk_args,
+                                                    query_limit);
                 if (ret) {
                         gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, 0,
                                 LG_MSG_FIND_OP_FAILED, "Find all operation "
@@ -851,6 +854,7 @@ void get_gfdb_methods (gfdb_methods_t *methods)
 {
         methods->init_db = init_db;
         methods->fini_db = fini_db;
+        methods->find_all = find_all;
         methods->find_unchanged_for_time = find_unchanged_for_time;
         methods->find_recently_changed_files = find_recently_changed_files;
         methods->find_unchanged_for_time_freq = find_unchanged_for_time_freq;
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;
diff --git a/libglusterfs/src/gfdb/gfdb_data_store_types.h b/libglusterfs/src/gfdb/gfdb_data_store_types.h
index d0c96370eb8..02b7aa0fd33 100644
--- a/libglusterfs/src/gfdb/gfdb_data_store_types.h
+++ b/libglusterfs/src/gfdb/gfdb_data_store_types.h
@@ -366,12 +366,18 @@ typedef int
  *                        for every record found
  *      _query_cbk_args : Custom argument passed for the call back
  *                        function query_callback
+ *      query_limit     : 0 - list all files
+ *                        positive value - add the LIMIT clause to
+ *                        the SQL query to limit the number of records
+ *                        returned
+ *
  * Returns : if successful return 0 or
  *          -ve value in case of failure*/
 typedef int
 (*gfdb_find_all_t)(void *db_conn,
                                gf_query_callback_t query_callback,
-                               void *_cbk_args);
+                               void *_cbk_args,
+                               int query_limit);
 
 
 
diff --git a/libglusterfs/src/gfdb/gfdb_sqlite3.c b/libglusterfs/src/gfdb/gfdb_sqlite3.c
index 094028361c5..4284ed9a69d 100644
--- a/libglusterfs/src/gfdb/gfdb_sqlite3.c
+++ b/libglusterfs/src/gfdb/gfdb_sqlite3.c
@@ -632,12 +632,15 @@ gf_get_basic_query_stmt (char **out_stmt)
  * */
 int
 gf_sqlite3_find_all (void *db_conn, gf_query_callback_t query_callback,
-                        void *query_cbk_args)
+                        void *query_cbk_args,
+                        int query_limit)
 {
         int ret                                 =       -1;
         char *query_str                         =       NULL;
         gf_sql_connection_t *sql_conn           =       db_conn;
         sqlite3_stmt *prep_stmt                 =       NULL;
+        char *limit_query                       =       NULL;
+        char *query                             =       NULL;
 
         CHECK_SQL_CONN (sql_conn, out);
         GF_VALIDATE_OR_GOTO(GFDB_STR_SQLITE3, query_callback, out);
@@ -647,12 +650,28 @@ gf_sqlite3_find_all (void *db_conn, gf_query_callback_t query_callback,
                 goto out;
         }
 
-        ret = sqlite3_prepare (sql_conn->sqlite3_db_conn, query_str, -1,
+        query = query_str;
+
+        if (query_limit > 0) {
+                ret = gf_asprintf (&limit_query, "%s LIMIT %d",
+                                   query, query_limit);
+                if (ret < 0) {
+                        gf_msg (GFDB_STR_SQLITE3, GF_LOG_ERROR, 0,
+                                LG_MSG_QUERY_FAILED,
+                                "Failed creating limit query statement");
+                        limit_query = NULL;
+                        goto out;
+                }
+
+                query = limit_query;
+        }
+
+        ret = sqlite3_prepare (sql_conn->sqlite3_db_conn, query, -1,
                                 &prep_stmt, 0);
         if (ret != SQLITE_OK) {
                 gf_msg (GFDB_STR_SQLITE3, GF_LOG_ERROR, 0,
-                        LG_MSG_PREPARE_FAILED, "Failed to prepare statement %s :"
-                        "%s", query_str,
+                        LG_MSG_PREPARE_FAILED,
+                        "Failed to prepare statement %s: %s", query,
                         sqlite3_errmsg (sql_conn->sqlite3_db_conn));
                 ret = -1;
                 goto out;
@@ -661,7 +680,7 @@ gf_sqlite3_find_all (void *db_conn, gf_query_callback_t query_callback,
         ret = gf_sql_query_function (prep_stmt, query_callback, query_cbk_args);
         if (ret) {
                 gf_msg (GFDB_STR_SQLITE3, GF_LOG_ERROR, 0, LG_MSG_QUERY_FAILED,
-                        "Failed Query %s", query_str);
+                        "Failed Query %s", query);
                 goto out;
         }
 
@@ -669,6 +688,10 @@ gf_sqlite3_find_all (void *db_conn, gf_query_callback_t query_callback,
 out:
         sqlite3_finalize (prep_stmt);
         GF_FREE (query_str);
+
+        if (limit_query)
+                GF_FREE (limit_query);
+
         return ret;
 }
 
@@ -1070,10 +1093,10 @@ gf_sqlite3_find_unchanged_for_time_freq (void *db_conn,
                 GF_COL_TB_WMSEC ") >= ? ) ) )"
                 " AND "
                 /*Second condition: For Reads
-                 * Files that have reaASCd wind time smaller than for_time
+                 * Files that have read wind time smaller than for_time
                  * OR
                  * File that have read wind time greater than for_time,
-                 * but write_frequency less than freq_write_cnt*/
+                 * but read_frequency less than freq_read_cnt*/
                 "( ((" GF_COL_TB_RWSEC " * " TOSTRING(GFDB_MICROSEC) " + "
                 GF_COL_TB_RWMSEC ") < ? )"
                 " OR "
diff --git a/libglusterfs/src/gfdb/gfdb_sqlite3.h b/libglusterfs/src/gfdb/gfdb_sqlite3.h
index 52b84da251c..5b55b0ace5e 100644
--- a/libglusterfs/src/gfdb/gfdb_sqlite3.h
+++ b/libglusterfs/src/gfdb/gfdb_sqlite3.h
@@ -258,7 +258,8 @@ int gf_sqlite3_delete (void *db_conn, gfdb_db_record_t *);
 
 /*querying modules*/
 int gf_sqlite3_find_all (void *db_conn, gf_query_callback_t,
-                        void *_query_cbk_args);
+                        void *_query_cbk_args,
+                        int query_limit);
 int gf_sqlite3_find_unchanged_for_time (void *db_conn,
                                         gf_query_callback_t query_callback,
                                         void *_query_cbk_args,
diff --git a/libglusterfs/src/tier-ctr-interface.h b/libglusterfs/src/tier-ctr-interface.h
new file mode 100644
index 00000000000..cfd3f8a5e5d
--- /dev/null
+++ b/libglusterfs/src/tier-ctr-interface.h
@@ -0,0 +1,44 @@
+#ifndef _TIER_CTR_INTERFACE_H_
+#define _TIER_CTR_INTERFACE_H_
+
+#include "common-utils.h"
+#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;
+        int query_limit;
+        gf_boolean_t emergency_demote;
+} gfdb_ipc_ctr_params_t;
+
+#endif