MXS-1633 Turn off collecting of sqlite3 memstats

According to customer reports collecting the statistics has a significant
impact on the performance. As we don't need that information we can just
as well turn off that.

Further, since maxscale-common now links to the sqlite3-library, no
module needs to do that explicitly.

server/core/CMakeLists.txt

@@ -73,6 +73,7 @@ target_link_libraries(maxscale-common
   z
   rt
   m
+  sqlite3
   stdc++
   gnutls
   gcrypt

server/core/gateway.cc

@@ -46,6 +46,7 @@
 #include <maxscale/paths.h>
 #include <maxscale/query_classifier.h>
 #include <maxscale/server.h>
+#include <maxscale/sqlite3.h>
 #include <maxscale/session.h>
 #include <maxscale/utils.h>
 #include <maxscale/version.h>
@@ -189,6 +190,7 @@ static void disable_module_unloading(const char* arg);
 static void enable_module_unloading(const char* arg);
 static void redirect_output_to_file(const char* arg);
 static bool user_is_acceptable(const char* specified_user);
+static bool init_sqlite3();
 
 struct DEBUG_ARGUMENT
 {
@@ -1957,6 +1959,13 @@ int main(int argc, char **argv)
         }
     }
 
+    if (!init_sqlite3())
+    {
+        MXS_ERROR("Could not initialize sqlite3, exiting.");
+        rc = MAXSCALE_INTERNALERROR;
+        goto return_main;
+    }
+
     MXS_NOTICE("MariaDB MaxScale %s started", MAXSCALE_VERSION);
     MXS_NOTICE("MaxScale is running in process %i", getpid());
 
@@ -3304,3 +3313,33 @@ static bool user_is_acceptable(const char* specified_user)
 
     return acceptable;
 }
+
+static bool init_sqlite3()
+{
+    bool rv = true;
+
+    // Collecting the memstatus introduces locking that, according to customer reports,
+    // has a significant impact on the performance.
+    if (sqlite3_config(SQLITE_CONFIG_MEMSTATUS, (int)0) == SQLITE_OK) // 0 turns off.
+    {
+        MXS_NOTICE("The collection of SQLite memory allocation statistics turned off.");
+    }
+    else
+    {
+        MXS_WARNING("Could not turn off the collection of SQLite memory allocation statistics.");
+        // Non-fatal, we simply will take a small performance hit.
+    }
+
+    if (sqlite3_config(SQLITE_CONFIG_MULTITHREAD) == SQLITE_OK)
+    {
+        MXS_NOTICE("Threading mode of SQLite set to Multi-thread.");
+    }
+    else
+    {
+        MXS_ERROR("Could not set the threading mode of SQLite to Multi-thread. "
+                  "MaxScale will terminate.");
+        rv = false;
+    }
+
+    return rv;
+}

server/modules/authenticator/MySQLAuth/CMakeLists.txt

@@ -2,7 +2,7 @@ if(SQLITE_VERSION VERSION_LESS 3.3)
   message(FATAL_ERROR "SQLite version 3.3 or higher is required")
 else()
   add_library(mysqlauth SHARED mysql_auth.c dbusers.c)
-  target_link_libraries(mysqlauth maxscale-common mysqlcommon sqlite3)
+  target_link_libraries(mysqlauth maxscale-common mysqlcommon)
   set_target_properties(mysqlauth PROPERTIES VERSION "1.0.0")
   install_module(mysqlauth core)
 endif()

server/modules/routing/avrorouter/CMakeLists.txt

@@ -4,7 +4,7 @@ if(AVRO_FOUND AND JANSSON_FOUND)
   add_library(avrorouter SHARED avro.c ../binlogrouter/binlog_common.c avro_client.c avro_schema.c avro_rbr.c avro_file.c avro_index.c)
   set_target_properties(avrorouter PROPERTIES VERSION "1.0.0")
   set_target_properties(avrorouter PROPERTIES LINK_FLAGS -Wl,-z,defs)
-  target_link_libraries(avrorouter maxscale-common ${JANSSON_LIBRARIES} ${AVRO_LIBRARIES} maxavro sqlite3 lzma)
+  target_link_libraries(avrorouter maxscale-common ${JANSSON_LIBRARIES} ${AVRO_LIBRARIES} maxavro lzma)
   install_module(avrorouter core)
 else()
   message(STATUS "No Avro C or Jansson libraries found, not building avrorouter.")

server/modules/routing/binlogrouter/CMakeLists.txt

@@ -1,11 +1,11 @@
 add_library(binlogrouter SHARED blr.c blr_master.c blr_cache.c blr_slave.c blr_file.c)
 set_target_properties(binlogrouter PROPERTIES INSTALL_RPATH ${CMAKE_INSTALL_RPATH}:${MAXSCALE_LIBDIR} VERSION "2.0.0")
 set_target_properties(binlogrouter PROPERTIES LINK_FLAGS -Wl,-z,defs)
-target_link_libraries(binlogrouter maxscale-common ${PCRE_LINK_FLAGS} uuid sqlite3)
+target_link_libraries(binlogrouter maxscale-common ${PCRE_LINK_FLAGS} uuid)
 install_module(binlogrouter core)
 
 add_executable(maxbinlogcheck maxbinlogcheck.c blr_file.c blr_cache.c blr_master.c blr_slave.c blr.c)
-target_link_libraries(maxbinlogcheck maxscale-common ${PCRE_LINK_FLAGS} uuid sqlite3)
+target_link_libraries(maxbinlogcheck maxscale-common ${PCRE_LINK_FLAGS} uuid)
 
 install_executable(maxbinlogcheck core)
 

server/modules/routing/binlogrouter/test/CMakeLists.txt

@@ -1,5 +1,5 @@
 if(BUILD_TESTS)
   add_executable(testbinlogrouter testbinlog.c ../blr.c ../blr_slave.c ../blr_master.c ../blr_file.c ../blr_cache.c)
-  target_link_libraries(testbinlogrouter maxscale-common ${PCRE_LINK_FLAGS} uuid sqlite3)
+  target_link_libraries(testbinlogrouter maxscale-common ${PCRE_LINK_FLAGS} uuid)
   add_test(NAME TestBinlogRouter COMMAND ./testbinlogrouter WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
 endif()