feat(s3stream): change append callback thread number (AutoMQ#1950)

Author: lifepuzzlefun

core/src/main/scala/kafka/log/streamaspect/ElasticLog.scala

@@ -12,7 +12,7 @@
 package kafka.log.streamaspect
 
 import com.automq.stream.api.{Client, CreateStreamOptions, KeyValue, OpenStreamOptions}
-import com.automq.stream.utils.FutureUtil
+import com.automq.stream.utils.{FutureUtil, Systems}
 import io.netty.buffer.Unpooled
 import kafka.log.LocalLog.CleanedFileSuffix
 import kafka.log._
@@ -588,8 +588,8 @@ object ElasticLog extends Logging {
     private val APPEND_TIME_HIST = KafkaMetricsGroup.newHistogram("AppendTimeNanos")
     private val APPEND_CALLBACK_TIME_HIST = KafkaMetricsGroup.newHistogram("AppendCallbackTimeNanos")
     private val APPEND_ACK_TIME_HIST = KafkaMetricsGroup.newHistogram("AppendAckTimeNanos")
-    private val APPEND_CALLBACK_EXECUTOR: Array[ExecutorService] = new Array[ExecutorService](8)
-    private val READ_ASYNC_EXECUTOR: Array[ExecutorService] = new Array[ExecutorService](8)
+    private val APPEND_CALLBACK_EXECUTOR: Array[ExecutorService] = new Array[ExecutorService](Systems.CPU_CORES * 2)
+    private val READ_ASYNC_EXECUTOR: Array[ExecutorService] = new Array[ExecutorService](Systems.CPU_CORES * 4)
 
     for (i <- APPEND_CALLBACK_EXECUTOR.indices) {
         APPEND_CALLBACK_EXECUTOR(i) = Executors.newSingleThreadExecutor(ThreadUtils.createThreadFactory("log-append-callback-executor-" + i, true))