...G...PS. [ZBX-7933] added configurable parameter for TCP queue maxi…

…mum size

ChangeLog.d/bugfix/ZBX-7933

@@ -0,0 +1 @@
+...G...PS. [ZBX-7933] added configurable parameter for TCP queue maximum size (dgoloscapov)

conf/zabbix_agentd.conf

@@ -511,3 +511,14 @@ Hostname=Zabbix server
 # Mandatory: no
 # Default:
 # TLSCipherAll=
+
+####### For advanced users - TCP-related fine-tuning parameters #######
+
+## Option: ListenBacklog
+#       The maximum number of pending connections in the queue. This parameter is passed to
+#       listen() function as argument 'backlog' (see "man listen").
+#
+# Mandatory: no
+# Range: 0 - INT_MAX (depends on system, too large values may be silently truncated to implementation-specified maximum)
+# Default: SOMAXCONN (hard-coded constant, depends on system)
+# ListenBacklog=

conf/zabbix_agentd.win.conf

@@ -470,3 +470,14 @@ Hostname=Windows host
 # Mandatory: no
 # Default:
 # TLSCipherAll=
+
+####### For advanced users - TCP-related fine-tuning parameters #######
+
+## Option: ListenBacklog
+#       The maximum number of pending connections in the queue. This parameter is passed to
+#       listen() function as argument 'backlog' (see "man listen").
+#
+# Mandatory: no
+# Range: 0 - INT_MAX (depends on system, too large values may be silently truncated to implementation-specified maximum)
+# Default: SOMAXCONN (hard-coded constant, depends on system)
+# ListenBacklog=

conf/zabbix_proxy.conf

@@ -901,3 +901,13 @@ StatsAllowedIP=127.0.0.1
 # Default:
 # VaultDBPath=
 
+####### For advanced users - TCP-related fine-tuning parameters #######
+
+## Option: ListenBacklog
+#       The maximum number of pending connections in the queue. This parameter is passed to
+#       listen() function as argument 'backlog' (see "man listen").
+#
+# Mandatory: no
+# Range: 0 - INT_MAX (depends on system, too large values may be silently truncated to implementation-specified maximum)
+# Default: SOMAXCONN (hard-coded constant, depends on system)
+# ListenBacklog=

conf/zabbix_server.conf

@@ -933,3 +933,14 @@ StatsAllowedIP=127.0.0.1
 # Range: 1-3600
 # Default:
 # ProblemHousekeepingFrequency=60
+
+####### For advanced users - TCP-related fine-tuning parameters #######
+
+## Option: ListenBacklog
+#       The maximum number of pending connections in the queue. This parameter is passed to
+#       listen() function as argument 'backlog' (see "man listen").
+#
+# Mandatory: no
+# Range: 0 - INT_MAX (depends on system, too large values may be silently truncated to implementation-specified maximum)
+# Default: SOMAXCONN (hard-coded constant, depends on system)
+# ListenBacklog=

src/go/pkg/zbxlib/globals_linux.go

@@ -86,6 +86,7 @@ char *CONFIG_TLS_CIPHER_CMD = NULL;
 
 int	CONFIG_PASSIVE_FORKS = 0;
 int	CONFIG_ACTIVE_FORKS = 0;
+int	CONFIG_TCP_MAX_BACKLOG_SIZE	= SOMAXCONN;
 
 const char	*progname = NULL;
 const char	title_message[] = "agent";

src/go/pkg/zbxlib/globals_windows.go

@@ -59,6 +59,8 @@ int	CONFIG_UNSAFE_USER_PARAMETERS= 0;
 int	CONFIG_ENABLE_REMOTE_COMMANDS= 0;
 char *CONFIG_SOURCE_IP = NULL;
 
+int	CONFIG_TCP_MAX_BACKLOG_SIZE	= SOMAXCONN;
+
 const char	*progname = NULL;
 const char	title_message[] = "agent";
 const char	*usage_message[] = {};

src/libs/zbxcomms/comms.c

@@ -48,6 +48,7 @@ extern ZBX_THREAD_LOCAL char	info_buf[256];
 #endif
 
 extern int	CONFIG_TIMEOUT;
+extern int	CONFIG_TCP_MAX_BACKLOG_SIZE;
 
 /******************************************************************************
  *                                                                            *
@@ -1146,7 +1147,7 @@ int	zbx_tcp_listen(zbx_socket_t *s, const char *listen_ip, unsigned short listen
 					goto out;
 			}
 
-			if (ZBX_PROTO_ERROR == listen(s->sockets[s->num_socks], SOMAXCONN))
+			if (ZBX_PROTO_ERROR == listen(s->sockets[s->num_socks], CONFIG_TCP_MAX_BACKLOG_SIZE))
 			{
 				zbx_set_socket_strerror("listen() for [[%s]:%s] failed: %s",
 						NULL != ip ? ip : "-", port,
@@ -1319,7 +1320,7 @@ int	zbx_tcp_listen(zbx_socket_t *s, const char *listen_ip, unsigned short listen
 			goto out;
 		}
 
-		if (ZBX_PROTO_ERROR == listen(s->sockets[s->num_socks], SOMAXCONN))
+		if (ZBX_PROTO_ERROR == listen(s->sockets[s->num_socks], CONFIG_TCP_MAX_BACKLOG_SIZE))
 		{
 			zbx_set_socket_strerror("listen() for [[%s]:%hu] failed: %s",
 					NULL != ip ? ip : "-", listen_port,

src/zabbix_agent/zabbix_agentd.c

@@ -93,6 +93,8 @@ char	*CONFIG_TLS_CIPHER_ALL		= NULL;
 char	*CONFIG_TLS_CIPHER_CMD13	= NULL;	/* not used in agent, defined for linking with tls.c */
 char	*CONFIG_TLS_CIPHER_CMD		= NULL;	/* not used in agent, defined for linking with tls.c */
 
+int	CONFIG_TCP_MAX_BACKLOG_SIZE	= SOMAXCONN;
+
 #ifndef _WINDOWS
 #	include "../libs/zbxnix/control.h"
 #	include "zbxmodules.h"
@@ -951,6 +953,8 @@ static void	zbx_load_config(int requirement, ZBX_TASK_EX *task)
 			PARM_OPT,	0,			0},
 		{"DenyKey",			load_key_access_rule,			TYPE_CUSTOM,
 			PARM_OPT,	0,			0},
+		{"ListenBacklog",		&CONFIG_TCP_MAX_BACKLOG_SIZE,		TYPE_INT,
+			PARM_OPT,	0,			INT_MAX},
 		{NULL}
 	};
 

src/zabbix_get/zabbix_get.c

@@ -184,6 +184,8 @@ char	*CONFIG_TLS_CIPHER_CMD		= NULL;	/* parameter '--tls-cipher' from zabbix_get
 int	CONFIG_PASSIVE_FORKS		= 0;	/* not used in zabbix_get, just for linking with tls.c */
 int	CONFIG_ACTIVE_FORKS		= 0;	/* not used in zabbix_get, just for linking with tls.c */
 
+int	CONFIG_TCP_MAX_BACKLOG_SIZE	= SOMAXCONN;
+
 /* COMMAND LINE OPTIONS */
 
 /* long options */

src/zabbix_proxy/proxy.c

@@ -309,6 +309,7 @@ char	*CONFIG_HISTORY_STORAGE_OPTS		= NULL;
 int	CONFIG_HISTORY_STORAGE_PIPELINES	= 0;
 
 char	*CONFIG_STATS_ALLOWED_IP	= NULL;
+int	CONFIG_TCP_MAX_BACKLOG_SIZE	= SOMAXCONN;
 
 int	CONFIG_DOUBLE_PRECISION		= ZBX_DB_DBL_PRECISION_ENABLED;
 
@@ -869,6 +870,8 @@ static void	zbx_load_config(ZBX_TASK_EX *task)
 			PARM_OPT,	1,			1000},
 		{"StartHistoryPollers",		&CONFIG_HISTORYPOLLER_FORKS,		TYPE_INT,
 			PARM_OPT,	0,			1000},
+		{"ListenBacklog",		&CONFIG_TCP_MAX_BACKLOG_SIZE,		TYPE_INT,
+			PARM_OPT,	0,			INT_MAX},
 		{NULL}
 	};
 

src/zabbix_sender/win32/zabbix_sender.c

@@ -31,6 +31,8 @@ const char	*help_message[] = {NULL};
 
 unsigned char	program_type	= ZBX_PROGRAM_TYPE_SENDER;
 
+int	CONFIG_TCP_MAX_BACKLOG_SIZE	= SOMAXCONN;
+
 int	zabbix_sender_send_values(const char *address, unsigned short port, const char *source,
 		const zabbix_sender_value_t *values, int count, char **result)
 {

src/zabbix_sender/zabbix_sender.c

@@ -293,6 +293,8 @@ char	*CONFIG_TLS_CIPHER_CMD		= NULL;	/* parameter '--tls-cipher' from sender com
 int	CONFIG_PASSIVE_FORKS		= 0;	/* not used in zabbix_sender, just for linking with tls.c */
 int	CONFIG_ACTIVE_FORKS		= 0;	/* not used in zabbix_sender, just for linking with tls.c */
 
+int	CONFIG_TCP_MAX_BACKLOG_SIZE	= SOMAXCONN;
+
 /* COMMAND LINE OPTIONS */
 
 /* long options */
@@ -870,6 +872,8 @@ static void	zbx_load_config(const char *config_file)
 			PARM_OPT,	0,			0},
 		{"TLSCipherPSK",		&cfg_tls_cipher_psk,			TYPE_STRING,
 			PARM_OPT,	0,			0},
+		{"ListenBacklog",		&CONFIG_TCP_MAX_BACKLOG_SIZE,		TYPE_INT,
+			PARM_OPT,	0,			INT_MAX},
 		{NULL}
 	};
 

src/zabbix_server/server.c

@@ -333,6 +333,7 @@ char	*CONFIG_HISTORY_STORAGE_OPTS		= NULL;
 int	CONFIG_HISTORY_STORAGE_PIPELINES	= 0;
 
 char	*CONFIG_STATS_ALLOWED_IP	= NULL;
+int	CONFIG_TCP_MAX_BACKLOG_SIZE	= SOMAXCONN;
 
 int	CONFIG_DOUBLE_PRECISION		= ZBX_DB_DBL_PRECISION_ENABLED;
 
@@ -934,6 +935,8 @@ static void	zbx_load_config(ZBX_TASK_EX *task)
 			PARM_OPT,	1,			3600},
 		{"ServiceManagerSyncFrequency",	&CONFIG_SERVICEMAN_SYNC_FREQUENCY,	TYPE_INT,
 			PARM_OPT,	1,			3600},
+		{"ListenBacklog",		&CONFIG_TCP_MAX_BACKLOG_SIZE,		TYPE_INT,
+			PARM_OPT,	0,			INT_MAX},
 		{NULL}
 	};
 

tests/zbxmocktest.c

@@ -177,6 +177,9 @@ char	*CONFIG_HISTORY_STORAGE_URL		= NULL;
 char	*CONFIG_HISTORY_STORAGE_OPTS		= NULL;
 int	CONFIG_HISTORY_STORAGE_PIPELINES	= 0;
 
+/* not used in tests, defined for linking with comms.c */
+int	CONFIG_TCP_MAX_BACKLOG_SIZE	= SOMAXCONN;
+
 const char	title_message[] = "mock_title_message";
 const char	*usage_message[] = {"mock_usage_message", NULL};
 const char	*help_message[] = {"mock_help_message", NULL};