Assign random seed for lmi dist (deepjavalibrary#912)

* Assign random seed

* review comments

* format Java

* Add comments

* format Python

* minor refactor

---------

Co-authored-by: Frank Liu <frankfliu2000@gmail.com>

engines/python/setup/djl_python/huggingface.py

@@ -206,7 +206,7 @@ def inference(self, inputs):
         parameters = []
         batch = inputs.get_batches()
         first = True
-        for item in batch:
+        for i, item in enumerate(batch):
             input_map = decode(item, content_type)
             _inputs = input_map.pop("inputs", input_map)
             if isinstance(_inputs, list):
@@ -224,6 +224,13 @@ def inference(self, inputs):
                         "In order to enable dynamic batching, all input batches must have the same parameters"
                     )
 
+            seed_key = 'seed' if inputs.is_batch() else f'batch_{i}.seed'
+            if item.contains_key(seed_key):
+                seed = parameters[i].get("seed")
+                if not seed:
+                    # set server provided seed if seed is not part of request
+                    parameters[i]["seed"] = item.get_as_string(key=seed_key)
+
         outputs = Output()
 
         if self.rolling_batch_type:

engines/python/setup/djl_python/rolling_batch/lmi_dist_rolling_batch.py

@@ -125,7 +125,7 @@ def preprocess_requests(self, requests, **kwargs):
                 top_p=param.get("top_p", 1.0),
                 typical_p=param.get("typical_p", 1.0),
                 do_sample=param.get("do_sample", False),
-            )
+                seed=int(param.get("seed", 0)))
             stop_parameters = StoppingCriteriaParameters(
                 stop_sequences=param.get("stop_sequences", []),
                 max_new_tokens=param.get("max_new_tokens", 30))

engines/python/src/main/java/ai/djl/python/engine/RollingBatch.java

@@ -19,6 +19,7 @@
 import ai.djl.translate.TranslateException;
 import ai.djl.util.JsonUtils;
 import ai.djl.util.PairList;
+import ai.djl.util.RandomUtils;
 
 import com.google.gson.JsonObject;
 
@@ -80,6 +81,11 @@ public void run() {
                         batch.setProperties(req.input.getProperties());
                     }
                     batch.add(prefix, req.getRequest());
+                    String seed = req.getSeed();
+                    if (seed != null) {
+                        String seedPrefix = "batch_" + i + ".seed";
+                        batch.add(seedPrefix, req.seed);
+                    }
                 }
                 batch.addProperty("batch_size", String.valueOf(size));
 
@@ -123,7 +129,7 @@ public Output addInput(Input input, int timeout) throws TranslateException {
                     throw new TranslateException("Time out in: " + timeout);
                 }
             }
-            Request req = new Request(input);
+            Request req = new Request(input, String.valueOf(RandomUtils.nextInt()));
             list.add(req);
             canRead.signal();
             return req.output;
@@ -147,12 +153,14 @@ private static final class Request {
         Output output;
         String nextToken;
         boolean last;
+        String seed;
 
-        Request(Input input) {
+        Request(Input input, String seed) {
             this.input = input;
             data = new ChunkedBytesSupplier();
             output = new Output();
             output.add(data);
+            this.seed = seed;
         }
 
         BytesSupplier getRequest() {
@@ -162,6 +170,20 @@ BytesSupplier getRequest() {
             return input.getData();
         }
 
+        /**
+         * Seed is required for LMI Dist for sampling for all processes in the MPI to generate the
+         * same token. NextTokenChooserParameters is constructed during first forward and preserved
+         * for all forward calls of the request.
+         *
+         * @return seed, only for first forward
+         */
+        String getSeed() {
+            if (nextToken != null) {
+                return null;
+            }
+            return seed;
+        }
+
         void addResponse(String json) {
             JsonObject element = JsonUtils.GSON.fromJson(json, JsonObject.class);
             last = element.get("last").getAsBoolean();