fix: async profiler max duration && reduce memory allocation when sending jfr (#733)

Author: zhengziyi0117

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/asyncprofiler/AsyncProfilerDataSender.java

@@ -100,6 +100,7 @@ public void sendData(AsyncProfilerTask task, File dumpFile) throws IOException,
                     GRPC_UPSTREAM_TIMEOUT, TimeUnit.SECONDS
             ).collect(new ClientResponseObserver<AsyncProfilerData, AsyncProfilerCollectionResponse>() {
                 ClientCallStreamObserver<AsyncProfilerData> requestStream;
+                final byte[] buf = new byte[DATA_CHUNK_SIZE];
 
                 @Override
                 public void beforeStart(ClientCallStreamObserver<AsyncProfilerData> requestStream) {
@@ -111,7 +112,6 @@ public void onNext(AsyncProfilerCollectionResponse value) {
                     if (AsyncProfilingStatus.TERMINATED_BY_OVERSIZE.equals(value.getType())) {
                         LOGGER.warn("JFR is too large to be received by the oap server");
                     } else {
-                        byte[] buf = new byte[DATA_CHUNK_SIZE];
                         try {
                             int bytesRead;
                             while ((bytesRead = fileInputStream.read(buf)) != -1) {

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/Config.java

@@ -262,9 +262,9 @@ public static class AsyncProfiler {
 
         /**
          * Max execution time(second) for the Async Profiler. The task will be stopped even if a longer time is specified.
-         * default 10min.
+         * default 20min.
          */
-        public static int MAX_DURATION = 600;
+        public static int MAX_DURATION = 1200;
 
         /**
          * Path for the JFR outputs from the Async Profiler.

apm-sniffer/config/agent.config

@@ -166,8 +166,8 @@ profile.dump_max_stack_depth=${SW_AGENT_PROFILE_DUMP_MAX_STACK_DEPTH:500}
 profile.snapshot_transport_buffer_size=${SW_AGENT_PROFILE_SNAPSHOT_TRANSPORT_BUFFER_SIZE:4500}
 # If true, async profiler will be enabled when user creates a new async profiler task. If false, it will be disabled. The default value is true.
 asyncprofiler.active=${SW_AGENT_ASYNC_PROFILER_ACTIVE:true}
-# Max execution time(second) for the Async Profiler. The task will be stopped even if a longer time is specified. default 10min.
-asyncprofiler.max_duration=${SW_AGENT_ASYNC_PROFILER_MAX_DURATION:600}
+# Max execution time(second) for the Async Profiler. The task will be stopped even if a longer time is specified. default 20min.
+asyncprofiler.max_duration=${SW_AGENT_ASYNC_PROFILER_MAX_DURATION:1200}
 # Path for the JFR outputs from the Async Profiler. If the parameter is not empty, the file will be created in the specified directory, otherwise the Files.createTemp method will be used to create the file.
 asyncprofiler.output_path=${SW_AGENT_ASYNC_PROFILER_OUTPUT_PATH:}
 # If true, the agent collects and reports metrics to the backend.