Fix EOF proxy errors

manifests/zcloud-prod2/hpautoscaler.yaml

@@ -4,4 +4,5 @@ metadata:
   name: delta-sharing-server-hpa
   namespace: default
 spec:
+  minReplicas: 3
   maxReplicas: 8

server/src/main/resources/logback.xml

@@ -7,6 +7,11 @@
     </encoder>
   </appender>
 
+  <!-- Native Hadoop libs are not present in the container image; the pure-Java
+       fallback works correctly for GCS-backed Delta tables. Suppress the WARN
+       so it doesn't pollute Cloud Logging. -->
+  <logger name="org.apache.hadoop.util.NativeCodeLoader" level="ERROR" />
+
   <root level="INFO">
     <appender-ref ref="GCP_JSON" />
   </root>

server/src/main/scala/io/delta/sharing/server/DeltaSharingService.scala

@@ -1252,6 +1252,7 @@ object DeltaSharingService {
         .defaultHostname(serverConfig.getHost)
         .disableDateHeader()
         .disableServerHeader()
+        .idleTimeout(java.time.Duration.ofSeconds(serverConfig.idleTimeoutSeconds))
         .requestTimeout(java.time.Duration.ofSeconds(serverConfig.requestTimeoutSeconds))
         .annotatedService(serverConfig.endpoint, service: Any)
       if (serverConfig.ssl == null) {

server/src/main/scala/io/delta/sharing/server/config/ServerConfig.scala

@@ -68,6 +68,10 @@ case class ServerConfig(
     @BeanProperty var refreshTokenTtlMs: Int,
     // Whether to emit performance/timing log lines for table queries and CDF requests.
     @BeanProperty var perfLoggingEnabled: Boolean,
+    // The idle connection timeout in seconds. Connections idle for longer than this are closed.
+    // Should be greater than the proxy's IdleConnTimeout to avoid stale-connection EOF errors.
+    // Set to 0 to use Armeria's built-in default (15 seconds).
+    @BeanProperty var idleTimeoutSeconds: Long,
     // Access logging configuration for tracking share data egress via structured logs.
     @BeanProperty var accessLogging: AccessLoggingConfig
 ) extends ConfigItem {
@@ -94,6 +98,7 @@ case class ServerConfig(
       queryTablePageTokenTtlMs = 259200000, // 3 days
       refreshTokenTtlMs = 3600000, // 1 hour
       perfLoggingEnabled = true,
+      idleTimeoutSeconds = 120,
       accessLogging = null
     )
   }