diff --git a/build.gradle b/build.gradle
index 52166c196..72622b8a5 100644
--- a/build.gradle
+++ b/build.gradle
@@ -190,7 +190,7 @@ jib {
         }
     }
     container {
-        jvmFlags = ['-XX:+UseG1GC', '-XX:+ExitOnOutOfMemoryError', '-XX:NativeMemoryTracking=summary', '-XX:+UnlockDiagnosticVMOptions', '-XX:GCLockerRetryAllocationCount=10', '--enable-preview']
+        jvmFlags = ['-XX:+UseG1GC', '-XX:+ExitOnOutOfMemoryError', '-Xms1024M', '-XX:NativeMemoryTracking=summary', '-XX:+UnlockDiagnosticVMOptions', '-XX:GCLockerRetryAllocationCount=10', '--enable-preview']
         mainClass = 'io.emeraldpay.dshackle.StarterKt'
         args = []
         ports = ['2448', '2449', '8545']
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/commons/FluxIntervalWrapper.kt b/src/main/kotlin/io/emeraldpay/dshackle/commons/FluxIntervalWrapper.kt
index 314a660e7..343376a8e 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/commons/FluxIntervalWrapper.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/commons/FluxIntervalWrapper.kt
@@ -1,8 +1,11 @@
 package io.emeraldpay.dshackle.commons
 
 import reactor.core.publisher.Flux
+import reactor.core.publisher.Mono
+import zmq.util.function.Supplier
 import java.time.Duration
 import java.util.concurrent.atomic.AtomicBoolean
+import java.util.function.Function
 
 object FluxIntervalWrapper {
 
@@ -11,8 +14,8 @@ object FluxIntervalWrapper {
     // which prevents performing the inner flatMap if it is not finished in the previous step
     fun <T> interval(
         period: Duration,
-        mapper: Flux<T>,
-        transformer: (Flux<Long>) -> Flux<Long>,
+        mapper: Supplier<Mono<T>>,
+        transformer: Function<Flux<Long>, Flux<Long>>,
     ): Flux<T> {
         val isProcessing = AtomicBoolean(false)
 
@@ -21,8 +24,8 @@ object FluxIntervalWrapper {
             .filter { !isProcessing.get() }
             .flatMap {
                 isProcessing.set(true)
-                mapper
-                    .doFinally { isProcessing.set(false) }
+                mapper.get()
+                    .doOnTerminate { isProcessing.set(false) }
             }
     }
 }
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpReader.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpReader.kt
index 93a9d273f..69cfaff9c 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpReader.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpReader.kt
@@ -31,7 +31,7 @@ abstract class HttpReader(
 
     init {
         val connectionProvider = ConnectionProvider.builder("dshackleConnectionPool")
-            .maxConnections(500)
+            .maxConnections(1500)
             .pendingAcquireMaxCount(1000)
             .pendingAcquireTimeout(Duration.ofSeconds(10))
             .build()
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumFinalizationDetector.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumFinalizationDetector.kt
index afffb61d1..0c8722f69 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumFinalizationDetector.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumFinalizationDetector.kt
@@ -2,6 +2,7 @@ package io.emeraldpay.dshackle.upstream.ethereum
 
 import com.fasterxml.jackson.module.kotlin.readValue
 import io.emeraldpay.dshackle.Chain
+import io.emeraldpay.dshackle.Defaults
 import io.emeraldpay.dshackle.Global
 import io.emeraldpay.dshackle.upstream.ChainRequest
 import io.emeraldpay.dshackle.upstream.Upstream
@@ -72,6 +73,7 @@ class EthereumFinalizationDetector : FinalizationDetector {
                         upstream
                             .getIngressReader()
                             .read(req)
+                            .timeout(Defaults.internalCallsTimeout)
                             .flatMap {
                                 it.requireResult().flatMap { result ->
                                     val block = Global.objectMapper.readValue<BlockJson<TransactionRefJson>>(result)
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/generic/GenericRpcHead.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/generic/GenericRpcHead.kt
index 2f66ef9b9..4b5e2e208 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/generic/GenericRpcHead.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/generic/GenericRpcHead.kt
@@ -26,7 +26,6 @@ import io.emeraldpay.dshackle.upstream.ValidateUpstreamSettingsResult
 import io.emeraldpay.dshackle.upstream.forkchoice.ForkChoice
 import reactor.core.Disposable
 import reactor.core.scheduler.Scheduler
-import reactor.kotlin.core.publisher.toFlux
 import java.time.Duration
 
 class GenericRpcHead(
@@ -49,8 +48,9 @@ class GenericRpcHead(
         refreshSubscription?.dispose()
         val base = FluxIntervalWrapper.interval(
             interval,
-            getLatestBlock(api).toFlux(),
-        ) { it.publishOn(headScheduler).filter { !isSyncing } }
+            { getLatestBlock(api) },
+            { it.publishOn(headScheduler).filter { !isSyncing } },
+        )
         refreshSubscription = super.follow(base)
     }
 
diff --git a/src/test/kotlin/io/emeraldpay/dshackle/upstream/ethereum/GenericWsHeadTest.kt b/src/test/kotlin/io/emeraldpay/dshackle/upstream/ethereum/GenericWsHeadTest.kt
index 49ddb9877..b405bad2a 100644
--- a/src/test/kotlin/io/emeraldpay/dshackle/upstream/ethereum/GenericWsHeadTest.kt
+++ b/src/test/kotlin/io/emeraldpay/dshackle/upstream/ethereum/GenericWsHeadTest.kt
@@ -444,10 +444,10 @@ class GenericWsHeadTest {
                 StepVerifier.create(wsHead.headLiveness())
                     .expectNext(HeadLivenessState.FATAL_ERROR)
                     .thenCancel()
-                    .verify(Duration.ofSeconds(1))
+                    .verify(Duration.ofSeconds(2))
             }
             .thenCancel()
-            .verify(Duration.ofSeconds(1))
+            .verify(Duration.ofSeconds(3))
 
         verify(connection, times(2)).callRpc(ChainRequest("eth_chainId", ListParams()))
         verify(connection, times(2)).callRpc(ChainRequest("net_version", ListParams()))