diff --git a/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystem.java b/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
index 85490c181..2341d335d 100644
--- a/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
+++ b/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
@@ -30,7 +30,6 @@ public class SeaweedFileSystem extends FileSystem {
     public static final String FS_SEAWEED_FILER_PORT = "fs.seaweed.filer.port";
 
     private static final Logger LOG = LoggerFactory.getLogger(SeaweedFileSystem.class);
-    private static int BUFFER_SIZE = 16 * 1024 * 1024;
 
     private URI uri;
     private Path workingDirectory = new Path("/");
@@ -61,8 +60,6 @@ public class SeaweedFileSystem extends FileSystem {
         port = (port == -1) ? FS_SEAWEED_DEFAULT_PORT : port;
         conf.setInt(FS_SEAWEED_FILER_PORT, port);
 
-        conf.setInt(IO_FILE_BUFFER_SIZE_KEY, BUFFER_SIZE);
-
         setConf(conf);
         this.uri = uri;
 
diff --git a/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedOutputStream.java b/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedOutputStream.java
index 209e32d0b..d62d74fb1 100644
--- a/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedOutputStream.java
+++ b/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedOutputStream.java
@@ -56,12 +56,12 @@ public class SeaweedOutputStream extends OutputStream {
         this.outputIndex = 0;
         this.writeOperations = new ConcurrentLinkedDeque<>();
 
-        this.maxConcurrentRequestCount = 4 * Runtime.getRuntime().availableProcessors();
+        this.maxConcurrentRequestCount = Runtime.getRuntime().availableProcessors();
 
         this.threadExecutor
                 = new ThreadPoolExecutor(maxConcurrentRequestCount,
                 maxConcurrentRequestCount,
-                10L,
+                120L,
                 TimeUnit.SECONDS,
                 new LinkedBlockingQueue<Runnable>());
         this.completionService = new ExecutorCompletionService<>(this.threadExecutor);
@@ -180,7 +180,7 @@ public class SeaweedOutputStream extends OutputStream {
         bufferToWrite.flip();
         int bytesLength = bufferToWrite.limit() - bufferToWrite.position();
 
-        if (threadExecutor.getQueue().size() >= maxConcurrentRequestCount * 2) {
+        if (threadExecutor.getQueue().size() >= maxConcurrentRequestCount) {
             waitForTaskToComplete();
         }
         final Future<Void> job = completionService.submit(() -> {
diff --git a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystem.java b/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
index 85490c181..2341d335d 100644
--- a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
+++ b/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
@@ -30,7 +30,6 @@ public class SeaweedFileSystem extends FileSystem {
     public static final String FS_SEAWEED_FILER_PORT = "fs.seaweed.filer.port";
 
     private static final Logger LOG = LoggerFactory.getLogger(SeaweedFileSystem.class);
-    private static int BUFFER_SIZE = 16 * 1024 * 1024;
 
     private URI uri;
     private Path workingDirectory = new Path("/");
@@ -61,8 +60,6 @@ public class SeaweedFileSystem extends FileSystem {
         port = (port == -1) ? FS_SEAWEED_DEFAULT_PORT : port;
         conf.setInt(FS_SEAWEED_FILER_PORT, port);
 
-        conf.setInt(IO_FILE_BUFFER_SIZE_KEY, BUFFER_SIZE);
-
         setConf(conf);
         this.uri = uri;
 
diff --git a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedInputStream.java b/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedInputStream.java
index 10ec9b3cc..6b3c72f7d 100644
--- a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedInputStream.java
+++ b/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedInputStream.java
@@ -2,7 +2,6 @@ package seaweed.hdfs;
 
 // based on org.apache.hadoop.fs.azurebfs.services.AbfsInputStream
 
-import com.google.common.base.Preconditions;
 import org.apache.hadoop.fs.FSExceptionMessages;
 import org.apache.hadoop.fs.FSInputStream;
 import org.apache.hadoop.fs.FileSystem.Statistics;
@@ -37,7 +36,7 @@ public class SeaweedInputStream extends FSInputStream {
             final Statistics statistics,
             final String path,
             final FilerProto.Entry entry,
-            final int bufferSize) {
+            final int bufferSize) throws IOException {
         this.filerGrpcClient = filerGrpcClient;
         this.statistics = statistics;
         this.path = path;
@@ -100,7 +99,7 @@ public class SeaweedInputStream extends FSInputStream {
             }
         }
 
-        return (int)bytesRead;
+        return (int) bytesRead;
 
     }
 
diff --git a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedOutputStream.java b/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedOutputStream.java
index c602a0d81..05805b9e5 100644
--- a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedOutputStream.java
+++ b/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedOutputStream.java
@@ -60,12 +60,12 @@ public class SeaweedOutputStream extends OutputStream implements Syncable, Strea
         this.outputIndex = 0;
         this.writeOperations = new ConcurrentLinkedDeque<>();
 
-        this.maxConcurrentRequestCount = 4 * Runtime.getRuntime().availableProcessors();
+        this.maxConcurrentRequestCount = Runtime.getRuntime().availableProcessors();
 
         this.threadExecutor
                 = new ThreadPoolExecutor(maxConcurrentRequestCount,
                 maxConcurrentRequestCount,
-                10L,
+                120L,
                 TimeUnit.SECONDS,
                 new LinkedBlockingQueue<Runnable>());
         this.completionService = new ExecutorCompletionService<>(this.threadExecutor);
@@ -113,7 +113,7 @@ public class SeaweedOutputStream extends OutputStream implements Syncable, Strea
                 break;
             }
 
-            // System.out.println(path + "     [" + (outputIndex + currentOffset) + "," + ((outputIndex + currentOffset) + writableBytes) + ")");
+            // System.out.println(path + "     [" + (outputIndex + currentOffset) + "," + ((outputIndex + currentOffset) + writableBytes) + ") " + buffer.capacity());
             buffer.put(data, currentOffset, writableBytes);
             outputIndex += writableBytes;
             currentOffset += writableBytes;
@@ -227,7 +227,7 @@ public class SeaweedOutputStream extends OutputStream implements Syncable, Strea
         bufferToWrite.flip();
         int bytesLength = bufferToWrite.limit() - bufferToWrite.position();
 
-        if (threadExecutor.getQueue().size() >= maxConcurrentRequestCount * 2) {
+        if (threadExecutor.getQueue().size() >= maxConcurrentRequestCount) {
             waitForTaskToComplete();
         }
         final Future<Void> job = completionService.submit(() -> {