From 768d0b3b3f53119bf6c2936538d642f45bbc3a02 Mon Sep 17 00:00:00 2001
From: Edward Oakes <ed.nmi.oakes@gmail.com>
Date: Thu, 12 Mar 2020 12:05:30 -0700
Subject: [PATCH] Allocate a buffer of 100 calls for each RPC handler (#7573)

---
 src/ray/rpc/grpc_server.cc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/ray/rpc/grpc_server.cc b/src/ray/rpc/grpc_server.cc
index 7c0e35e26..8de493c09 100644
--- a/src/ray/rpc/grpc_server.cc
+++ b/src/ray/rpc/grpc_server.cc
@@ -66,7 +66,12 @@ void GrpcServer::Run() {
   // Create calls for all the server call factories.
   for (auto &entry : server_call_factories_) {
     for (int i = 0; i < num_threads_; i++) {
-      entry->CreateCall();
+      // Create a buffer of 100 calls for each RPC handler.
+      // TODO(edoakes): a small buffer should be fine and seems to have better
+      // performance, but we don't currently handle backpressure on the client.
+      for (int j = 0; j < 100; j++) {
+        entry->CreateCall();
+      }
     }
   }
   // Start threads that polls incoming requests.