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, 10 insertions, 0 deletions

diff --git a/libglusterfs/src/gfdb/gfdb_data_store_types.h b/libglusterfs/src/gfdb/gfdb_data_store_types.h
index 2d3c5ede99c..ab8b7945d2c 100644
--- a/libglusterfs/src/gfdb/gfdb_data_store_types.h
+++ b/libglusterfs/src/gfdb/gfdb_data_store_types.h
@@ -651,6 +651,13 @@ typedef int
 
 typedef int (*gfdb_clear_files_heat_t)(void *db_conn);
 
+typedef int (*gfdb_get_db_version_t)(void *db_conn,
+                                        char **version);
+
+typedef int (*gfdb_get_db_setting_t)(void *db_conn,
+                                char *param_key,
+                                char **param_value);
+
 
 /*Data structure holding all the above plugin function pointers*/
 typedef struct gfdb_db_operations {
@@ -666,6 +673,8 @@ typedef struct gfdb_db_operations {
         gfdb_find_recently_changed_files_freq_t
                                         find_recently_changed_files_freq_op;
         gfdb_clear_files_heat_t clear_files_heat_op;
+        gfdb_get_db_version_t           get_db_version;
+        gfdb_get_db_setting_t           get_db_setting;
 } gfdb_db_operations_t;
 
 /*******************************************************************************
@@ -709,6 +718,7 @@ typedef struct gfdb_connection {
                         gf_msg (comp_name, GF_LOG_ERROR, 0,\
                                 LG_MSG_SET_PARAM_FAILED, "Failed setting %s "\
                                 "to params dictionary", param_key);\
+                        data_destroy (data);\
                         goto error;\
                 };\
         } while (0)