We have faced situation when using CDR and CEL by sqlite3 modules. With system having high load (~100 concurrent calls created by sipp) we found many cdr and cel records missed. There is special finction in sqlite3, that make able to fix this situation - sqlite3_wait_timeout, that also can replace awful code cdr_sqlite3 ad cel_sqlite3 modules. Also this function can be used for aastdb and res_config_sqlite3 to avoid missed writes to sqlite db.

cdr/cdr_sqlite3_custom.c

@@ -228,7 +228,6 @@ static int write_cdr(struct ast_cdr *cdr)
 	int res = 0;
 	char *error = NULL;
 	char *sql = NULL;
-	int count = 0;
 
 	if (db == NULL) {
 		/* Should not have loaded, but be failsafe. */
@@ -264,16 +263,7 @@ static int write_cdr(struct ast_cdr *cdr)
 		ast_free(value_string);
 	}
 
-	/* XXX This seems awful arbitrary... */
-	for (count = 0; count < 5; count++) {
-		res = sqlite3_exec(db, sql, NULL, NULL, &error);
-		if (res != SQLITE_BUSY && res != SQLITE_LOCKED) {
-			break;
-		}
-		usleep(200);
-	}
-
-	if (error) {
+	if (sqlite3_exec(db, sql, NULL, NULL, &error) != SQLITE_OK) {
 		ast_log(LOG_ERROR, "%s. SQL: %s.\n", error, sql);
 		sqlite3_free(error);
 	}
@@ -317,7 +307,7 @@ static int load_module(void)
 		free_config(0);
 		return AST_MODULE_LOAD_DECLINE;
 	}
-
+	sqlite3_busy_timeout(db, 1000);
 	/* is the table there? */
 	sql = sqlite3_mprintf("SELECT COUNT(AcctId) FROM %q;", table);
 	res = sqlite3_exec(db, sql, NULL, NULL, NULL);

cel/cel_sqlite3_custom.c

@@ -234,7 +234,6 @@ static void write_cel(struct ast_event *event)
 {
 	char *error = NULL;
 	char *sql = NULL;
-	int count = 0;
 
 	if (db == NULL) {
 		/* Should not have loaded, but be failsafe. */
@@ -269,18 +268,7 @@ static void write_cel(struct ast_event *event)
 		ast_free(value_string);
 	}
 
-	/* XXX This seems awful arbitrary... */
-	for (count = 0; count < 5; count++) {
-		int res = sqlite3_exec(db, sql, NULL, NULL, &error);
-		if (res != SQLITE_BUSY && res != SQLITE_LOCKED) {
-			break;
-		}
-		usleep(200);
-	}
-
-	ast_mutex_unlock(&lock);
-
-	if (error) {
+	if (sqlite3_exec(db, sql, NULL, NULL, &error) != SQLITE_OK) {
 		ast_log(LOG_ERROR, "%s. SQL: %s.\n", error, sql);
 		sqlite3_free(error);
 	}
@@ -288,6 +276,7 @@ static void write_cel(struct ast_event *event)
 	if (sql) {
 		sqlite3_free(sql);
 	}
+	ast_mutex_unlock(&lock);
 
 	return;
 }
@@ -320,7 +309,7 @@ static int load_module(void)
 		free_config();
 		return AST_MODULE_LOAD_DECLINE;
 	}
-
+	sqlite3_busy_timeout(db, 1000);
 	/* is the table there? */
 	sql = sqlite3_mprintf("SELECT COUNT(*) FROM %q;", table);
 	res = sqlite3_exec(db, sql, NULL, NULL, NULL);

main/db.c

@@ -257,6 +257,7 @@ static int db_open(void)
 		ast_mutex_unlock(&dblock);
 		return -1;
 	}
+
 	ast_mutex_unlock(&dblock);
 
 	return 0;
@@ -283,9 +284,8 @@ static int db_execute_sql(const char *sql, int (*callback)(void *, int, char **,
 	char *errmsg = NULL;
 	int res =0;
 
-	sqlite3_exec(astdb, sql, callback, arg, &errmsg);
-	if (errmsg) {
-		ast_log(LOG_WARNING, "Error executing SQL: %s\n", errmsg);
+	if (sqlite3_exec(astdb, sql, callback, arg, &errmsg) != SQLITE_OK) {
+		ast_log(LOG_WARNING, "Error executing SQL (%s): %s\n", sql, errmsg);
 		sqlite3_free(errmsg);
 		res = -1;
 	}

res/res_config_sqlite3.c

@@ -324,6 +324,7 @@ static int db_open(struct realtime_sqlite3_db *db)
 		ao2_unlock(db);
 		return -1;
 	}
+	sqlite3_busy_timeout(db->handle, 1000);
 
 	if (db->debug) {
 		sqlite3_trace(db->handle, trace_cb, db);