Tunable backlog size for IC

4 files changed, 5 insertions, 1 deletions

diff --git a/library/cpp/actors/interconnect/interconnect_common.h b/library/cpp/actors/interconnect/interconnect_common.h
index aa2cbe9a191..d3130380943 100644
--- a/library/cpp/actors/interconnect/interconnect_common.h
+++ b/library/cpp/actors/interconnect/interconnect_common.h
@@ -50,6 +50,7 @@ namespace NActors {
         ui32 NumPreallocatedBuffers = 16;
         bool EnableExternalDataChannel = false;
         bool ValidateIncomingPeerViaDirectLookup = false;
+        ui32 SocketBacklogSize = 0; // SOMAXCONN if zero
 
         ui32 GetSendBufferSize() const {
             ui32 res = 512 * 1024; // 512 kb is the default value for send buffer
diff --git a/library/cpp/actors/interconnect/interconnect_tcp_server.cpp b/library/cpp/actors/interconnect/interconnect_tcp_server.cpp
index aad8677ca46..ede35b0b8b0 100644
--- a/library/cpp/actors/interconnect/interconnect_tcp_server.cpp
+++ b/library/cpp/actors/interconnect/interconnect_tcp_server.cpp
@@ -46,9 +46,10 @@ namespace NActors {
             if (addr.GetFamily() == AF_INET6) {
                 SetSockOpt(*Listener, IPPROTO_IPV6, IPV6_V6ONLY, 0);
             }
+            const ui32 backlog = ProxyCommonCtx->Settings.SocketBacklogSize;
             if (const auto e = -Listener->Bind(addr)) {
                 return e;
-            } else if (const auto e = -Listener->Listen(SOMAXCONN)) {
+            } else if (const auto e = -Listener->Listen(backlog ? backlog : SOMAXCONN)) {
                 return e;
             } else {
                 return 0;
diff --git a/ydb/core/driver_lib/run/kikimr_services_initializers.cpp b/ydb/core/driver_lib/run/kikimr_services_initializers.cpp
index 24672d25aeb..51eba3cae4d 100644
--- a/ydb/core/driver_lib/run/kikimr_services_initializers.cpp
+++ b/ydb/core/driver_lib/run/kikimr_services_initializers.cpp
@@ -578,6 +578,7 @@ static TInterconnectSettings GetInterconnectSettings(const NKikimrConfig::TInter
     if (config.HasValidateIncomingPeerViaDirectLookup()) {
         result.ValidateIncomingPeerViaDirectLookup = config.GetValidateIncomingPeerViaDirectLookup();
     }
+    result.SocketBacklogSize = config.GetSocketBacklogSize();
 
     return result;
 }
diff --git a/ydb/core/protos/config.proto b/ydb/core/protos/config.proto
index aedc48a26fc..807bd4fc7ab 100644
--- a/ydb/core/protos/config.proto
+++ b/ydb/core/protos/config.proto
@@ -440,6 +440,7 @@ message TInterconnectConfig {
     optional uint32 NumPreallocatedBuffers = 41;
     optional bool EnableExternalDataChannel = 42;
     optional bool ValidateIncomingPeerViaDirectLookup = 44;
+    optional uint32 SocketBacklogSize = 45; // SOMAXCONN if not set or zero
 
     // ballast is added to IC handshake frames to ensure correctness of jumbo frames transmission over network
     optional uint32 HandshakeBallastSize = 14;