From: Aki Tuomi <aki.tuomi@dovecot.fi>
Date: Tue, 31 Jan 2017 17:43:30 +0000 (+0200)
Subject: driver-cassandra: Add support for speculative execution
X-Git-Tag: 2.3.0.rc1~2128
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=07038d3a12a915e98f794566f56a0ed12e0653eb;p=thirdparty%2Fdovecot%2Fcore.git

driver-cassandra: Add support for speculative execution
---

diff --git a/m4/want_cassandra.m4 b/m4/want_cassandra.m4
index 22159e9fc7..0648d5228e 100644
--- a/m4/want_cassandra.m4
+++ b/m4/want_cassandra.m4
@@ -6,6 +6,9 @@ AC_DEFUN([DOVECOT_WANT_CASSANDRA], [
   
                           AC_DEFINE(HAVE_CASSANDRA,, [Build with Cassandra support])
                           found_sql_drivers="$found_sql_drivers cassandra"
+                          AC_CHECK_LIB(cassandra, cass_cluster_set_constant_speculative_execution_policy, [
+                                       AC_DEFINE(HAVE_CASSANDRA_SPECULATIVE_POLICY, 1, [Cassandra supports speculative execution policy])
+                          ])
                   ], [
                     if test $want_cassandra = yes; then
                       AC_ERROR([Can't build with Cassandra support: cassandra.h not found])
diff --git a/src/lib-sql/driver-cassandra.c b/src/lib-sql/driver-cassandra.c
index a30eb0e50c..0f80113d97 100644
--- a/src/lib-sql/driver-cassandra.c
+++ b/src/lib-sql/driver-cassandra.c
@@ -85,6 +85,7 @@ struct cassandra_db {
 	unsigned int connect_timeout_msecs, request_timeout_msecs;
 	unsigned int warn_timeout_msecs;
 	unsigned int heartbeat_interval_secs, idle_timeout_secs;
+	unsigned int execution_retry_interval_msecs, execution_retry_times;
 	in_port_t port;
 
 	CassCluster *cluster;
@@ -494,6 +495,18 @@ static void driver_cassandra_parse_connect_string(struct cassandra_db *db,
 		} else if (strcmp(key, "metrics") == 0) {
 			i_free(db->metrics_path);
 			db->metrics_path = i_strdup(value);
+		} else if (strcmp(key, "execution_retry_interval") == 0) {
+			if (settings_get_time_msecs(value, &db->execution_retry_interval_msecs, &error) < 0)
+				i_fatal("cassandra: Invalid execution_retry_interval '%s': %s", value, error);
+#ifndef HAVE_CASSANDRA_SPECULATIVE_POLICY
+			i_fatal("cassandra: This cassandra version does not support execution_retry_interval");
+#endif
+		} else if (strcmp(key, "execution_retry_times") == 0) {
+			if (str_to_uint(value, &db->execution_retry_times) < 0)
+				i_fatal("cassandra: Invalid execution_retry_times %s", value);
+#ifndef HAVE_CASSANDRA_SPECULATIVE_POLICY
+			i_fatal("cassandra: This cassandra version does not support execution_retry_times");
+#endif
 		} else {
 			i_fatal("cassandra: Unknown connect string: %s", key);
 		}
@@ -623,6 +636,10 @@ static struct sql_db *driver_cassandra_init_v(const char *connect_string)
 		cass_cluster_set_connection_heartbeat_interval(db->cluster, db->heartbeat_interval_secs);
 	if (db->idle_timeout_secs != 0)
 		cass_cluster_set_connection_idle_timeout(db->cluster, db->idle_timeout_secs);
+#ifdef HAVE_CASSANDRA_SPECULATIVE_POLICY
+	if (db->execution_retry_times > 0 && db->execution_retry_interval_msecs > 0)
+		cass_cluster_set_constant_speculative_execution_policy(db->cluster, db->execution_retry_interval_msecs, db->execution_retry_times);
+#endif
 	db->session = cass_session_new();
 	if (db->metrics_path != NULL)
 		db->to_metrics = timeout_add(1000, driver_cassandra_metrics_write, db);
@@ -853,6 +870,9 @@ static void driver_cassandra_result_send_query(struct cassandra_result *result)
 	result->statement = cass_statement_new(result->query, 0);
 	cass_statement_set_consistency(result->statement, result->consistency);
 
+#ifdef HAVE_CASSANDRA_SPECULATIVE_POLICY
+	cass_statement_set_is_idempotent(result->statement, cass_true);
+#endif
 	future = cass_session_execute(db->session, result->statement);
 	driver_cassandra_set_callback(future, db, query_callback, result);
 }