Dynamic size

CHUNKED_UPLOAD_GUIDE.md

@@ -101,7 +101,13 @@ Same as the traditional `/api/cf/deploy` endpoint.
 ## Client Implementation Example (JavaScript)
 
 ```javascript
-const CHUNK_SIZE = 5 * 1024 * 1024; // 5MB
+// You can use ANY chunk size - server supports variable chunk sizes!
+// Recommended: 1-2MB for Tanzu with memory constraints
+const CHUNK_SIZE = 1 * 1024 * 1024; // 1MB
+// Other options:
+// const CHUNK_SIZE = 512 * 1024;      // 512KB (very safe)
+// const CHUNK_SIZE = 2 * 1024 * 1024; // 2MB (balanced)
+// const CHUNK_SIZE = 5 * 1024 * 1024; // 5MB (if you have memory)
 
 async function deployWithChunks(jarFile, manifestFile, deploymentConfig) {
   const apiBase = 'https://your-app.example.com/api/cf';
@@ -191,7 +197,8 @@ deployWithChunks(jarInput.files[0], manifestInput.files[0], config)
 import requests
 import os
 
-CHUNK_SIZE = 5 * 1024 * 1024  # 5MB
+# You can use ANY chunk size!
+CHUNK_SIZE = 1 * 1024 * 1024  # 1MB (recommended for Tanzu)
 
 def deploy_with_chunks(api_base, jar_path, manifest_path, deployment_config):
     # Step 1: Initialize upload session
@@ -316,13 +323,13 @@ server {
 
 ```properties
 # Chunked Upload Configuration
-cf.upload.chunk.size=5242880
 cf.upload.session.timeout-minutes=30
 ```
 
-- **cf.upload.chunk.size**: Size of each chunk in bytes (default: 5MB)
 - **cf.upload.session.timeout-minutes**: How long inactive sessions are kept (default: 30 minutes)
 
+**Note:** There is NO server-side chunk size configuration. The server accepts ANY chunk size from the client. Chunks are appended sequentially as they arrive.
+
 ## Session Management
 
 - Upload sessions expire after 30 minutes of inactivity (configurable)
@@ -356,17 +363,22 @@ The traditional `/api/cf/deploy` endpoint remains available and functional. You
 
 ## Performance Considerations
 
-- **Chunk size**: 5MB is a good balance between request count and size
-  - Smaller chunks = more requests but safer for proxies
-  - Larger chunks = fewer requests but may hit proxy limits
+- **Chunk size**: Client controls this completely
+  - **Smaller chunks (512KB-1MB)**: More requests, but safer for memory-constrained servers and strict proxies
+  - **Larger chunks (5-10MB)**: Fewer requests, faster uploads, but needs more memory
+  - **Recommended for Tanzu**: 1MB (good balance for low-memory environments)
+  - **Any size works**: Server accepts variable chunk sizes
 
-- **Parallel uploads**: Current implementation is sequential
-  - Files are uploaded one chunk at a time
-  - Chunks must be uploaded in order (0, 1, 2, ...)
+- **Sequential upload requirement**: **CRITICAL**
+  - Chunks **MUST** be uploaded in order: 0, 1, 2, 3...
+  - Server validates and enforces sequential order
+  - Out-of-order chunks will be rejected
+  - This is necessary because chunks are appended sequentially to the file
 
 - **Network reliability**: Chunked uploads are more resilient
   - Failed chunks can be retried individually
   - No need to re-upload the entire file on failure
+  - Just retry the specific failed chunk index
 
 ## Monitoring
 

src/main/java/com/cfdeployer/service/ChunkedUploadService.java

@@ -61,13 +61,21 @@ public class ChunkedUploadService {
                             fileType, fileState.getTotalChunks(), totalChunks));
         }
 
-        // Write chunk to file using streaming to avoid loading entire chunk into memory
+        // Write chunk to file using sequential append mode
+        // This supports variable chunk sizes - chunks MUST be uploaded in order (0, 1, 2, ...)
         Path targetPath = fileState.getTargetPath();
-        long offset = (long) chunkIndex * getChunkSize();
 
-        try (RandomAccessFile raf = new RandomAccessFile(targetPath.toFile(), "rw");
-             var inputStream = chunk.getInputStream()) {
-            raf.seek(offset);
+        // Verify chunks are uploaded in order
+        if (chunkIndex != fileState.getReceivedChunkCount()) {
+            throw new IllegalArgumentException(
+                    String.format("Chunks must be uploaded in order. Expected chunk %d but received %d",
+                            fileState.getReceivedChunkCount(), chunkIndex));
+        }
+
+        try (var inputStream = chunk.getInputStream();
+             var outputStream = Files.newOutputStream(targetPath,
+                     java.nio.file.StandardOpenOption.CREATE,
+                     java.nio.file.StandardOpenOption.APPEND)) {
 
             // Stream chunk data in smaller buffers to reduce memory pressure
             byte[] buffer = new byte[8192]; // 8KB buffer
@@ -75,12 +83,12 @@ public class ChunkedUploadService {
             long totalWritten = 0;
 
             while ((bytesRead = inputStream.read(buffer)) != -1) {
-                raf.write(buffer, 0, bytesRead);
+                outputStream.write(buffer, 0, bytesRead);
                 totalWritten += bytesRead;
             }
 
-            log.debug("Wrote chunk {} ({} bytes) to {} at offset {}",
-                    chunkIndex, totalWritten, targetPath.getFileName(), offset);
+            log.debug("Appended chunk {} ({} bytes) to {}",
+                    chunkIndex, totalWritten, targetPath.getFileName());
         }
 
         fileState.markChunkReceived(chunkIndex);
@@ -160,11 +168,6 @@ public class ChunkedUploadService {
         }
     }
 
-    private int getChunkSize() {
-        // Default chunk size - should match client-side
-        return 5 * 1024 * 1024; // 5MB
-    }
-
     public int getActiveSessionCount() {
         return activeSessions.size();
     }

src/main/resources/application.properties

@@ -16,10 +16,10 @@ cf.cli.timeout=600
 cf.cli.path=
 
 # Chunked Upload Configuration
-# Reduced chunk size to 2MB to avoid memory issues on low-memory Tanzu instances
-cf.upload.chunk.size=2097152
 # Session timeout in minutes (default: 30 minutes)
 cf.upload.session.timeout-minutes=30
+# Note: Chunk size is controlled by the client, not the server.
+# Server accepts any chunk size and appends chunks sequentially.
 
 # Logging Configuration
 logging.level.root=INFO