From 4be12c9ecb9ea8bf1fcd71aba99fd32abf7d131c Mon Sep 17 00:00:00 2001
From: Jason Wang <jason.ruonan.wang@gmail.com>
Date: Thu, 26 Aug 2021 23:40:27 -0400
Subject: [PATCH] auto select mhs engine if file has .tier0 suffix

---
 source/adios2/core/IO.cpp              | 4 ++++
 source/adios2/engine/mhs/MhsReader.cpp | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/source/adios2/core/IO.cpp b/source/adios2/core/IO.cpp
index 51b40067f9..5134f7d641 100644
--- a/source/adios2/core/IO.cpp
+++ b/source/adios2/core/IO.cpp
@@ -574,6 +574,10 @@ Engine &IO::Open(const std::string &name, const Mode mode, helper::Comm comm)
                 engineTypeLC = "bp";
                 engineTypeLC.push_back(v);
             }
+            else if (adios2sys::SystemTools::FileIsDirectory(name + ".tier0"))
+            {
+                engineTypeLC = "mhs";
+            }
             else
             {
                 if (helper::EndsWith(name, ".bp", false))
diff --git a/source/adios2/engine/mhs/MhsReader.cpp b/source/adios2/engine/mhs/MhsReader.cpp
index dbea352876..996fbd4fa1 100644
--- a/source/adios2/engine/mhs/MhsReader.cpp
+++ b/source/adios2/engine/mhs/MhsReader.cpp
@@ -22,7 +22,7 @@ MhsReader::MhsReader(IO &io, const std::string &name, const Mode mode,
 : Engine("MhsReader", io, name, mode, std::move(comm))
 {
     helper::GetParameter(io.m_Parameters, "Tiers", m_Tiers);
-    Params params = {{"tiers", std::to_string(m_Tiers)}};
+    Params params = {{"Tiers", std::to_string(m_Tiers)}};
     m_SiriusCompressor = std::make_shared<compress::CompressSirius>(params);
     io.SetEngine("");
     m_SubIOs.emplace_back(&io);