[Minor] Fuzzy upstream error threshold config

It would be nice to be able to configure `max_errors` and `revive_time`
for fuzzy check module for low traffic systems.

When traffic volume is relatively low an error rate builds at very slow
rate and it would take a while to reach default 40% threshold. At the
same time waiting for 60s sometimes could be unreasonable for dynamic
environments to re-resolve rspamd fuzzy storage.

1 files changed, 44 insertions, 0 deletions

diff --git a/src/plugins/fuzzy_check.c b/src/plugins/fuzzy_check.c
index a0e4df012..311bd3945 100644
--- a/src/plugins/fuzzy_check.c
+++ b/src/plugins/fuzzy_check.c
@@ -52,6 +52,8 @@
 
 #define DEFAULT_IO_TIMEOUT 500
 #define DEFAULT_RETRANSMITS 3
+#define DEFAULT_MAX_ERRORS 4
+#define DEFAULT_REVIVE_TIME 60
 #define DEFAULT_PORT 11335
 
 #define RSPAMD_FUZZY_PLUGIN_VERSION RSPAMD_FUZZY_VERSION
@@ -98,6 +100,8 @@ struct fuzzy_ctx {
 	struct rspamd_keypair_cache *keypairs_cache;
 	guint32 io_timeout;
 	guint32 retransmits;
+	guint   max_errors;
+	gdouble revive_time;
 	gint check_mime_part_ref; /* Lua callback */
 	gint process_rule_ref; /* Lua callback */
 	gint cleanup_rules_ref;
@@ -461,6 +465,10 @@ fuzzy_parse_rule (struct rspamd_config *cfg, const ucl_object_t *obj,
 
 	if ((value = ucl_object_lookup (obj, "servers")) != NULL) {
 		rule->servers = rspamd_upstreams_create (cfg->ups_ctx);
+		/* pass max_error and revive_time configuration in upstream for fuzzy storage
+		 * it allows to configure error_rate threshold and upstream dead timer
+		 */
+		rspamd_upstreams_set_limits (rule->servers, (gdouble) fuzzy_module_ctx->revive_time, NAN, NAN, NAN, (guint) fuzzy_module_ctx->max_errors, NAN);
 
 		rspamd_mempool_add_destructor (cfg->cfg_pool,
 				(rspamd_mempool_destruct_t)rspamd_upstreams_destroy,
@@ -718,6 +726,24 @@ fuzzy_check_module_init (struct rspamd_config *cfg, struct module_ctx **ctx)
 			0);
 	rspamd_rcl_add_doc_by_path (cfg,
 			"fuzzy_check",
+			"Maximum number of upstream errors, affects error rate threshold",
+			"max_errors",
+			UCL_INT,
+			NULL,
+			0,
+			NULL,
+			0);
+	rspamd_rcl_add_doc_by_path (cfg,
+			"fuzzy_check",
+			"Time to lapse before re-resolve faulty upstream",
+			"revive_time",
+			UCL_FLOAT,
+			NULL,
+			0,
+			NULL,
+			0);
+	rspamd_rcl_add_doc_by_path (cfg,
+			"fuzzy_check",
 			"Whitelisted IPs map",
 			"whitelist",
 			UCL_STRING,
@@ -1000,6 +1026,24 @@ fuzzy_check_module_config (struct rspamd_config *cfg)
 
 	if ((value =
 		rspamd_config_get_module_opt (cfg, "fuzzy_check",
+		"max_errors")) != NULL) {
+		fuzzy_module_ctx->max_errors = ucl_obj_toint (value);
+	}
+	else {
+		fuzzy_module_ctx->max_errors = DEFAULT_MAX_ERRORS;
+	}
+
+	if ((value =
+		rspamd_config_get_module_opt (cfg, "fuzzy_check",
+		"revive_time")) != NULL) {
+		fuzzy_module_ctx->revive_time = ucl_obj_todouble (value);
+	}
+	else {
+		fuzzy_module_ctx->revive_time = DEFAULT_REVIVE_TIME;
+	}
+
+	if ((value =
+		rspamd_config_get_module_opt (cfg, "fuzzy_check",
 		"whitelist")) != NULL) {
 		rspamd_config_radix_from_ucl (cfg, value, "Fuzzy whitelist",
 				&fuzzy_module_ctx->whitelist, NULL);