tier/ctr: Solving DB Lock issue due to write contention from db connections

Problem: The DB on the brick is been accessed by CTR, for write and
tier migrator, for read and write. The write from tier migrator is reseting
the heat counters after a cycle. Since we are using sqlite, two connections
trying to write would cause a db lock contention. As a result CTR used to fail
to update the db.

Solution: Using the same db connection of CTR for reseting the heat counters.
1) Introducted a new IPC FOP for CTR
2) After the query do a ipc syncop to the underlying client xlator associated
   to the brick.
3) CTR in brick will catch the IPC FOP and cleat the heat counters.

Change-Id: I53306bfc08dcdba479deb4ccc154896521336150
BUG: 1260730
Signed-off-by: Joseph Fernandes <josferna@redhat.com>
Reviewed-on: http://review.gluster.org/12031
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>
Tested-by: Dan Lambright <dlambrig@redhat.com>

7 files changed, 80 insertions, 23 deletions

diff --git a/libglusterfs/src/common-utils.h b/libglusterfs/src/common-utils.h
index 2b1290a4380..77a8cdd51c7 100644
--- a/libglusterfs/src/common-utils.h
+++ b/libglusterfs/src/common-utils.h
@@ -126,6 +126,7 @@ enum _gf_client_pid
 
 enum _gf_xlator_ipc_targets {
         GF_IPC_TARGET_CHANGELOG = 0,
+        GF_IPC_TARGET_CTR = 1
 };
 
 typedef enum _gf_boolean gf_boolean_t;
diff --git a/libglusterfs/src/gfdb/gfdb_data_store.c b/libglusterfs/src/gfdb/gfdb_data_store.c
index e1786a6ab06..9ea9150f3c3 100644
--- a/libglusterfs/src/gfdb/gfdb_data_store.c
+++ b/libglusterfs/src/gfdb/gfdb_data_store.c
@@ -678,6 +678,40 @@ find_recently_changed_files_freq(gfdb_conn_node_t *_conn_node,
 
 }
 
+
+
+/*Libgfdb API Function: Clear the heat for all the files
+ *
+ *  Arguments:
+ *    _conn_node              : GFDB Connection node
+ *
+ * Returns : if successful return 0 or
+ *           -ve value in case of failure
+ **/
+
+int
+clear_files_heat (gfdb_conn_node_t *_conn_node) {
+        int ret = 0;
+        gfdb_db_operations_t *db_operations_t   = NULL;
+        void *gf_db_connection                  = NULL;
+
+        CHECK_CONN_NODE(_conn_node);
+
+        db_operations_t = &_conn_node->gfdb_connection.gfdb_db_operations;
+        gf_db_connection = _conn_node->gfdb_connection.gf_db_connection;
+
+        if (db_operations_t->clear_files_heat_op) {
+                ret =  db_operations_t->clear_files_heat_op (gf_db_connection);
+                if (ret) {
+                        gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, 0,
+                                LG_MSG_FIND_OP_FAILED,
+                                "Clear files heat operation failed!");
+                }
+        }
+
+        return ret;
+}
+
 void get_gfdb_methods (gfdb_methods_t *methods)
 {
         methods->init_db = init_db;
@@ -686,5 +720,4 @@ void get_gfdb_methods (gfdb_methods_t *methods)
         methods->find_recently_changed_files = find_recently_changed_files;
         methods->find_unchanged_for_time_freq = find_unchanged_for_time_freq;
         methods->find_recently_changed_files_freq = find_recently_changed_files_freq;
-        methods->dbpath = strdup(GFDB_SQL_PARAM_DBPATH);
 }
diff --git a/libglusterfs/src/gfdb/gfdb_data_store.h b/libglusterfs/src/gfdb/gfdb_data_store.h
index 57f3de18f1c..5e46162b1ea 100644
--- a/libglusterfs/src/gfdb/gfdb_data_store.h
+++ b/libglusterfs/src/gfdb/gfdb_data_store.h
@@ -236,6 +236,19 @@ typedef int (*find_recently_changed_files_freq_t) (gfdb_conn_node_t *_conn_node,
                                                    int read_freq_thresold,
                                                    gf_boolean_t _clear_counters);
 
+
+
+/*Libgfdb API Function: Clear the heat for all the files
+ *
+ * Arguments:
+ *  _conn_node              : GFDB Connection node
+ *
+ * Returns : if successful return 0 or
+ *          -ve value in case of failure
+ **/
+int
+clear_files_heat (gfdb_conn_node_t *_conn_node);
+
 typedef struct gfdb_methods_s {
         init_db_t init_db;
         fini_db_t fini_db;
@@ -250,4 +263,5 @@ void get_gfdb_methods (gfdb_methods_t *methods);
 
 typedef void (*get_gfdb_methods_t) (gfdb_methods_t *methods);
 
+
 #endif
diff --git a/libglusterfs/src/gfdb/gfdb_data_store_types.h b/libglusterfs/src/gfdb/gfdb_data_store_types.h
index f44c4872c5b..2d3c5ede99c 100644
--- a/libglusterfs/src/gfdb/gfdb_data_store_types.h
+++ b/libglusterfs/src/gfdb/gfdb_data_store_types.h
@@ -649,6 +649,7 @@ typedef int
                                         gf_boolean_t _clear_counters);
 
 
+typedef int (*gfdb_clear_files_heat_t)(void *db_conn);
 
 
 /*Data structure holding all the above plugin function pointers*/
@@ -664,10 +665,9 @@ typedef struct gfdb_db_operations {
                                         find_unchanged_for_time_freq_op;
         gfdb_find_recently_changed_files_freq_t
                                         find_recently_changed_files_freq_op;
+        gfdb_clear_files_heat_t clear_files_heat_op;
 } gfdb_db_operations_t;
 
-
-
 /*******************************************************************************
  *
  * Database connection object: This objected is maitained by libgfdb for each
diff --git a/libglusterfs/src/gfdb/gfdb_sqlite3.c b/libglusterfs/src/gfdb/gfdb_sqlite3.c
index 4b1163d3ce4..f5f494f53a7 100644
--- a/libglusterfs/src/gfdb/gfdb_sqlite3.c
+++ b/libglusterfs/src/gfdb/gfdb_sqlite3.c
@@ -248,6 +248,8 @@ gf_sqlite3_fill_db_operations(gfdb_db_operations_t  *gfdb_db_ops)
                         gf_sqlite3_find_unchanged_for_time_freq;
         gfdb_db_ops->find_recently_changed_files_freq_op =
                         gf_sqlite3_find_recently_changed_files_freq;
+
+        gfdb_db_ops->clear_files_heat_op = gf_sqlite3_clear_files_heat;
 }
 
 
@@ -726,15 +728,6 @@ gf_sqlite3_find_recently_changed_files(void *db_conn,
                 goto out;
         }
 
-        /*Clear freq counters of un-selected data*/
-        ret = gf_sql_clear_counters(sql_conn);
-        if (ret) {
-                gf_msg (GFDB_STR_SQLITE3, GF_LOG_ERROR, 0,
-                        LG_MSG_CLEAR_COUNTER_FAILED, "Failed clearing"
-                        " counters!");
-                goto out;
-        }
-
         ret = 0;
 out:
         sqlite3_finalize(prep_stmt);
@@ -820,15 +813,6 @@ gf_sqlite3_find_unchanged_for_time (void *db_conn,
                 goto out;
         }
 
-        /*Clear freq counters of un-selected data*/
-        ret = gf_sql_clear_counters(sql_conn);
-        if (ret) {
-                gf_msg (GFDB_STR_SQLITE3, GF_LOG_ERROR, 0,
-                        LG_MSG_CLEAR_COUNTER_FAILED, "Failed clearing"
-                        " counters!");
-                goto out;
-        }
-
         ret = 0;
 out:
         sqlite3_finalize(prep_stmt);
@@ -1134,3 +1118,26 @@ out:
         sqlite3_finalize(prep_stmt);
         return ret;
 }
+
+
+int
+gf_sqlite3_clear_files_heat (void *db_conn)
+{
+        int ret = -1;
+        gf_sql_connection_t *sql_conn           =       db_conn;
+
+        CHECK_SQL_CONN (sql_conn, out);
+
+        ret = gf_sql_clear_counters (sql_conn);
+        if (ret) {
+                gf_msg (GFDB_STR_SQLITE3, GF_LOG_ERROR, 0,
+                        LG_MSG_CLEAR_COUNTER_FAILED, "Failed clearing "
+                        "files heat!");
+                goto out;
+        }
+
+        ret = 0;
+out:
+        return ret;
+}
+
diff --git a/libglusterfs/src/gfdb/gfdb_sqlite3.h b/libglusterfs/src/gfdb/gfdb_sqlite3.h
index 213693136fe..7bcba5a54bd 100644
--- a/libglusterfs/src/gfdb/gfdb_sqlite3.h
+++ b/libglusterfs/src/gfdb/gfdb_sqlite3.h
@@ -279,6 +279,8 @@ int gf_sqlite3_find_recently_changed_files_freq (void *db_conn,
                                         int read_freq_cnt,
                                         gf_boolean_t clear_counters);
 
+int gf_sqlite3_clear_files_heat (void *db_conn);
+
 void gf_sqlite3_fill_db_operations (gfdb_db_operations_t  *gfdb_db_ops);
 
 #endif
diff --git a/libglusterfs/src/gfdb/gfdb_sqlite3_helper.c b/libglusterfs/src/gfdb/gfdb_sqlite3_helper.c
index 0e27e00ed05..0cc294a5410 100644
--- a/libglusterfs/src/gfdb/gfdb_sqlite3_helper.c
+++ b/libglusterfs/src/gfdb/gfdb_sqlite3_helper.c
@@ -1195,10 +1195,10 @@ gf_sql_clear_counters (gf_sql_connection_t *sql_conn)
 
         CHECK_SQL_CONN (sql_conn, out);
 
-        query_str = "BEGIN;UPDATE "
+        query_str = "UPDATE "
                     GF_FILE_TABLE
                     " SET " GF_COL_READ_FREQ_CNTR " = 0 , "
-                    GF_COL_WRITE_FREQ_CNTR " = 0 ;COMMIT;";
+                    GF_COL_WRITE_FREQ_CNTR " = 0 ;";
 
         ret = sqlite3_exec (sql_conn->sqlite3_db_conn, query_str, NULL, NULL,
                                 &sql_strerror);