smp-server: limit direct RSLV per client

src/Simplex/Messaging/Server.hs

@@ -1550,7 +1550,7 @@ client
         Nothing -> incStat (rslvDisabled st) $> Nothing
         Just nenv -> pure (Just nenv)
     -- Runs on a forked thread so RSLV does not block other commands;
-    -- concurrency is limited by serverResolverConcurrency in forkCmd.
+    -- concurrency is limited in forkCmd by serverClientConcurrency for direct and serverResolverConcurrency for forwarded RSLV.
     resolveNameMsg :: VersionSMP -> NamesEnv -> NameQuery -> M s BrokerMsg
     resolveNameMsg v nenv q = do
       st <- asks (rslvStats . serverStats)
@@ -1580,7 +1580,7 @@ client
       Cmd SProxyService (RFWD encBlock) -> (response . (corrId, NoEntity,) =<<) <$> processForwardedCommand encBlock
       Cmd SResolver (RSLV d) -> rslvNamesEnv >>= \case
         Nothing -> pure $ response (corrId, NoEntity, ERR (NAME NO_RESOLVER))
-        Just nenv -> forkCmd serverResolverConcurrency corrId NoEntity (ERR $ NAME $ RESOLVER "timeout") (resolveNameMsg (thVersion thParams') nenv d)
+        Just nenv -> forkCmd serverClientConcurrency corrId NoEntity (ERR $ NAME $ RESOLVER "timeout") (resolveNameMsg (thVersion thParams') nenv d)
       Cmd SSenderLink command -> case command of
         LKEY k -> withQueue $ \q qr -> checkMode QMMessaging qr $ secureQueue_ q k $>> getQueueLink_ q qr
         LGET -> withQueue $ \q qr -> checkContact qr $ getQueueLink_ q qr

src/Simplex/Messaging/Server/Env/STM.hs

@@ -201,7 +201,7 @@ data ServerConfig s = ServerConfig
     smpAgentCfg :: SMPClientAgentConfig,
     allowSMPProxy :: Bool, -- auth is the same with `newQueueBasicAuth`
     serverClientConcurrency :: Int,
-    -- | max concurrent name resolutions per connection, enforced in forkCmd.
+    -- | max concurrent forwarded name resolutions per proxy connection, enforced in forkCmd.
     -- Much higher than serverClientConcurrency: forwarded RSLVs from many clients
     -- aggregate over a single proxy->relay connection (only servers send proxied
     -- requests), so bounding them by the per-client limit would throttle unduly.

src/Simplex/Messaging/Server/Main/Init.hs

@@ -154,7 +154,7 @@ iniFileContent cfgPath logPath opts host basicAuth controlPortPwds =
         \# `socks_mode` can be 'onion' for SOCKS proxy to be used for .onion destination hosts only (default)\n\
         \# or 'always' to be used for all destination hosts (can be used if it is an .onion server).\n\
         \# socks_mode = onion\n\n\
-        \# Limit number of threads a client can spawn to process proxy commands in parrallel.\n"
+        \# Limit number of threads a client can spawn to process proxy commands and name resolutions in parallel.\n"
     <> ("# client_concurrency = " <> tshow defaultProxyClientConcurrency)
     <> "\n\n\
         \[NAMES]\n\
@@ -169,7 +169,7 @@ iniFileContent cfgPath logPath opts host basicAuth controlPortPwds =
         \# resolver_auth: basic <username>:<password>\n\
         \# resolver_timeout_ms: 3000\n\
         \# resolver_max_response_bytes: 16000\n\
-        \# Max concurrent name resolutions per connection (forwarded RSLVs from many\n\
+        \# Max concurrent forwarded name resolutions per proxy connection (forwarded RSLVs from many\n\
         \# clients share one proxy connection, so this is much higher than PROXY client_concurrency).\n"
     <> ("# resolver_concurrency = " <> tshow defaultNameResolverConcurrency)
     <> "\n\n\

tests/RSLVTests.hs

@@ -108,7 +108,7 @@ rslvTests = do
     it "a name with subnames is sent as text" testSubnameKeepsItsLabels
     it "a record naming a different name is rejected" testRslvWrongName
   describe "RSLV resource use" $ do
-    it "one connection has at most resolver_concurrency lookups in flight" testRslvConnectionCap
+    it "one connection has at most client_concurrency lookups in flight" testRslvConnectionCap
     it "a lookup waiting for a slot runs when a slot is released" testRslvSlotWait
     it "a lookup waiting for a slot fails when the client times out" testRslvSlotWaitTimeout
 
@@ -289,7 +289,7 @@ testRslvWrongName =
 testRslvConnectionCap :: IO ()
 testRslvConnectionCap =
   NRS.withResolverServerDelayed 3000 (NRS.resolveResp status200 "{}") $ \port reqs ->
-    withSmpServerConfigOn (transport @TLS) (updateCfg (withNames port memCfg) $ \c -> c {serverResolverConcurrency = connCap}) testPort $ const $
+    withSmpServerConfigOn (transport @TLS) (updateCfg (withNames port memCfg) $ \c -> c {serverClientConcurrency = connCap}) testPort $ const $
       testSMPClient @TLS $ \h -> do
         sendRslvs h "cap" 16
         threadDelay 800000
@@ -335,7 +335,7 @@ slotWaitCfg port clientTimeout =
     let aCfg = smpAgentCfg c
         cCfg = smpCfg aCfg
         nt = NetworkTimeout {backgroundTimeout = clientTimeout, interactiveTimeout = clientTimeout}
-     in c {serverResolverConcurrency = 4, prometheusInterval = Just 1, smpAgentCfg = aCfg {smpCfg = cCfg {networkConfig = (networkConfig cCfg) {tcpTimeout = nt}}}}
+     in c {serverClientConcurrency = 4, prometheusInterval = Just 1, smpAgentCfg = aCfg {smpCfg = cCfg {networkConfig = (networkConfig cCfg) {tcpTimeout = nt}}}}
 
 data SlotWaitMetrics = SlotWaitMetrics {waits :: Int, waitTimeouts :: Int, waitMaxMs :: Int, waitSumMs :: Int}