tier/ctr: Solution for db locks for tier migrator and ctr using sqlite version less than 3.7 i.e rhel 6.7

Problem: On RHEL 6.7, we have sqlite version 3.6.2 which doesnt support
WAL journaling mode, as this journaling mode is only available in sqlite 3.7 and above.
As a result we cannot have to progreses concurrently accessing sqlite, without
running into db locks! Well WAL is also need for performace on CTR side.

Solution: This solution is to use CTR db connection for doing queries when WAL mode is
absent. i,e tier migrator will send sync_op ipc calls to CTR, which in turn will
do the query and create/update the query file suggested by tier migrator.

Pending: Well this solution will stop the db locks but the performance is still an issue for CTR.
We are developing an in-Memory Transaction Log (iMeTaL) which will help boost the CTR
performance by doing in memory udpates on the IO path and later flush the updates to
the db in a batch/segment flush.

Change-Id: Ie3149643ded159234b5cc6aa6cf93b9022c2f124
BUG: 1240577
Signed-off-by: Joseph Fernandes <josferna@redhat.com>
Signed-off-by: Dan Lambright <dlambrig@redhat.com>
Signed-off-by: Joseph Fernandes <josferna@redhat.com>
Reviewed-on: http://review.gluster.org/12191
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Luis Pabon <lpabon@redhat.com>

1 files changed, 87 insertions, 18 deletions

diff --git a/libglusterfs/src/gfdb/gfdb_data_store.c b/libglusterfs/src/gfdb/gfdb_data_store.c
index e409e0ddc69..af4be2116d0 100644
--- a/libglusterfs/src/gfdb/gfdb_data_store.c
+++ b/libglusterfs/src/gfdb/gfdb_data_store.c
@@ -236,7 +236,7 @@ init_db (dict_t *args, gfdb_db_type_t gfdb_db_type)
         if (!_conn_node) {
                 gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, ENOMEM,
                         LG_MSG_NO_MEMORY, "Failed mem alloc for "
-                        "gfdb_conn_node_t!");
+                        "gfdb_conn_node_t");
                 goto alloc_failed;
         }
 
@@ -384,7 +384,7 @@ insert_record (gfdb_conn_node_t *_conn_node,
                 if (ret) {
                         gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, 0,
                                 LG_MSG_INSERT_OR_UPDATE_FAILED, "Insert/Update"
-                                " operation failed!");
+                                " operation failed");
                 }
         }
 
@@ -424,7 +424,7 @@ delete_record (gfdb_conn_node_t *_conn_node,
                 if (ret) {
                         gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, 0,
                                 LG_MSG_DELETE_FAILED, "Delete operation "
-                                "failed!");
+                                "failed");
                 }
 
         }
@@ -464,7 +464,7 @@ find_all(gfdb_conn_node_t *_conn_node, gf_query_callback_t query_callback,
                 if (ret) {
                         gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, 0,
                                 LG_MSG_FIND_OP_FAILED, "Find all operation "
-                                "failed!");
+                                "failed");
                 }
 
         }
@@ -511,7 +511,7 @@ find_unchanged_for_time(gfdb_conn_node_t *_conn_node,
                 if (ret) {
                         gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, 0,
                                 LG_MSG_FIND_OP_FAILED, "Find unchanged "
-                                "operation failed!");
+                                "operation failed");
                 }
 
         }
@@ -556,7 +556,7 @@ find_recently_changed_files(gfdb_conn_node_t *_conn_node,
                 if (ret) {
                         gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, 0,
                                 LG_MSG_FIND_OP_FAILED,
-                                "Find changed operation failed!");
+                                "Find changed operation failed");
                 }
 
         }
@@ -613,7 +613,7 @@ find_unchanged_for_time_freq(gfdb_conn_node_t *_conn_node,
                 if (ret) {
                         gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, 0,
                                 LG_MSG_FIND_OP_FAILED,
-                                "Find unchanged with freq operation failed!");
+                                "Find unchanged with freq operation failed");
                 }
 
         }
@@ -669,7 +669,7 @@ find_recently_changed_files_freq(gfdb_conn_node_t *_conn_node,
                 if (ret) {
                         gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, 0,
                                 LG_MSG_FIND_OP_FAILED,
-                                "Find changed with freq operation failed!");
+                                "Find changed with freq operation failed");
                 }
 
         }
@@ -683,35 +683,100 @@ 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
+ *    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) {
+clear_files_heat (gfdb_conn_node_t *conn_node) {
         int ret = 0;
-        gfdb_db_operations_t *db_operations_t   = NULL;
+        gfdb_db_operations_t *db_operations   = NULL;
         void *gf_db_connection                  = NULL;
 
-        CHECK_CONN_NODE(_conn_node);
+        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;
+        db_operations = &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 (db_operations->clear_files_heat_op) {
+                ret =  db_operations->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!");
+                                "Clear files heat operation failed");
+                }
+        }
+
+        return ret;
+}
+
+
+/* Libgfdb API Function: Function to extract version of the db
+ * Input:
+ * gfdb_conn_node_t *conn_node        : GFDB Connection node
+ * char **version  : the version is extracted as a string and will be stored in
+ *                   this variable. The freeing of the memory should be done by
+ *                   the caller.
+ * Return:
+ *      On success return the lenght of the version string that is
+ *      extracted.
+ *      On failure return -1
+ * */
+int
+get_db_version (gfdb_conn_node_t *conn_node, char **version)
+{
+        int ret = 0;
+        gfdb_db_operations_t *db_operations   = NULL;
+        void *gf_db_connection                  = NULL;
+
+        CHECK_CONN_NODE(conn_node);
+
+        db_operations = &conn_node->gfdb_connection.gfdb_db_operations;
+        gf_db_connection = conn_node->gfdb_connection.gf_db_connection;
+
+        if (db_operations->get_db_version) {
+                ret =  db_operations->get_db_version (gf_db_connection,
+                                                        version);
+                if (ret < 0) {
+                        gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, 0,
+                                LG_MSG_FIND_OP_FAILED,
+                                "Get version failed");
                 }
         }
 
         return ret;
 }
 
+int
+get_db_setting (gfdb_conn_node_t *conn_node, char *param_key,
+                char **param_value)
+{
+        int ret = -1;
+        gfdb_db_operations_t *db_operations   = NULL;
+        void *gf_db_connection                  = NULL;
+
+        CHECK_CONN_NODE(conn_node);
+
+        db_operations = &conn_node->gfdb_connection.gfdb_db_operations;
+        gf_db_connection = conn_node->gfdb_connection.gf_db_connection;
+
+        if (db_operations->get_db_setting) {
+                ret =  db_operations->get_db_setting (gf_db_connection,
+                                                        param_key, param_value);
+                if (ret < 0) {
+                        gf_msg (GFDB_DATA_STORE, GF_LOG_ERROR, 0,
+                                LG_MSG_FIND_OP_FAILED,
+                                "Get setting failed");
+                }
+        }
+
+        return ret;
+}
+
+
+
 static const
 char *get_db_path_key()
 {
@@ -725,7 +790,11 @@ void get_gfdb_methods (gfdb_methods_t *methods)
         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;
-        methods->find_recently_changed_files_freq = find_recently_changed_files_freq;
+        methods->find_recently_changed_files_freq =
+                                               find_recently_changed_files_freq;
+        methods->clear_files_heat = clear_files_heat;
+        methods->get_db_version = get_db_version;
+        methods->get_db_setting = get_db_setting;
         methods->get_db_path_key = get_db_path_key;
 }