From 9eb770900fb428c3e37d5f53c573c057b2cd5ad2 Mon Sep 17 00:00:00 2001
From: Bob Bird <robertbird@google.com>
Date: Tue, 12 Nov 2024 11:59:51 -0700
Subject: [PATCH] Defend against -1 values for n_nodes (and update examples)

---
 examples/basic_hostname_config.yaml                         | 2 +-
 lib/ramble/docs/tutorials/mirrors.rst                       | 4 ++--
 lib/ramble/ramble/experiment_set.py                         | 6 ++++++
 lib/ramble/ramble/test/cmd/config.py                        | 2 +-
 lib/ramble/ramble/test/end_to_end/passthrough_variables.py  | 2 +-
 .../applications/iperf2/examples/manual_run/ramble.yaml     | 2 +-
 6 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/examples/basic_hostname_config.yaml b/examples/basic_hostname_config.yaml
index f069699c5..8c19ca283 100644
--- a/examples/basic_hostname_config.yaml
+++ b/examples/basic_hostname_config.yaml
@@ -13,7 +13,7 @@ ramble:
   variables:
     mpi_command: mpirun
     batch_submit: '{execute_experiment}'
-    processes_per_node: -1
+    processes_per_node: 1
   applications:
     hostname:
       workloads:
diff --git a/lib/ramble/docs/tutorials/mirrors.rst b/lib/ramble/docs/tutorials/mirrors.rst
index a15b8a7a0..fb694d513 100644
--- a/lib/ramble/docs/tutorials/mirrors.rst
+++ b/lib/ramble/docs/tutorials/mirrors.rst
@@ -54,7 +54,7 @@ Write the following configuration into the file, save, and exit:
       variables:
         mpi_command: mpirun -n {n_ranks}
         batch_submit: '{execute_experiment}'
-        processes_per_node: -1
+        processes_per_node: 1
       applications:
         wrfv4:
           variables:
@@ -84,7 +84,7 @@ will look something like this:
       variables:
         mpi_command: mpirun -n {n_ranks}
         batch_submit: '{execute_experiment}'
-        processes_per_node: -1
+        processes_per_node: 1
       applications:
         wrfv4:
           variables:
diff --git a/lib/ramble/ramble/experiment_set.py b/lib/ramble/ramble/experiment_set.py
index 9e2241f03..a29c88d52 100644
--- a/lib/ramble/ramble/experiment_set.py
+++ b/lib/ramble/ramble/experiment_set.py
@@ -214,12 +214,18 @@ def _compute_mpi_vars(self, expander, variables):
 
         if n_ranks:
             n_ranks = int(expander.expand_var(n_ranks))
+            if n_ranks <= 0:
+                logger.error("n_ranks must be positive")
 
         if ppn:
             ppn = int(expander.expand_var(ppn))
+            if ppn <= 0:
+                logger.error("processes_per_node must be positive")
 
         if n_nodes:
             n_nodes = int(expander.expand_var(n_nodes))
+            if n_nodes <= 0:
+                logger.error("n_nodes must be positive")
 
         if n_threads:
             n_threads = int(expander.expand_var(n_threads))
diff --git a/lib/ramble/ramble/test/cmd/config.py b/lib/ramble/ramble/test/cmd/config.py
index ae3fe85cc..fdb333c3b 100644
--- a/lib/ramble/ramble/test/cmd/config.py
+++ b/lib/ramble/ramble/test/cmd/config.py
@@ -685,7 +685,7 @@ def test_config_add_to_workspace_preserve_comments(
               variables:
                 n_ranks: '1'
                 n_nodes: '1'
-                processors_per_node: '1'
+                processes_per_node: '1'
 """
     with open(filepath, "w") as f:
         f.write(contents)
diff --git a/lib/ramble/ramble/test/end_to_end/passthrough_variables.py b/lib/ramble/ramble/test/end_to_end/passthrough_variables.py
index 1abf74408..d21966ba5 100644
--- a/lib/ramble/ramble/test/end_to_end/passthrough_variables.py
+++ b/lib/ramble/ramble/test/end_to_end/passthrough_variables.py
@@ -82,7 +82,7 @@ def test_disable_passthrough(mutable_config, mutable_mock_workspace_path):
 ramble:
   variables:
    batch_submit: '{execute_experiment}'
-   processes_per_node: -1
+   processes_per_node: 1
   applications:
     hostname:
       workloads:
diff --git a/var/ramble/repos/builtin/applications/iperf2/examples/manual_run/ramble.yaml b/var/ramble/repos/builtin/applications/iperf2/examples/manual_run/ramble.yaml
index 9e6e8d7be..dd8d5b135 100644
--- a/var/ramble/repos/builtin/applications/iperf2/examples/manual_run/ramble.yaml
+++ b/var/ramble/repos/builtin/applications/iperf2/examples/manual_run/ramble.yaml
@@ -23,7 +23,7 @@ ramble:
   variables:
     mpi_command: ''
     batch_submit: '{execute_experiment}'
-    processes_per_node: -1
+    processes_per_node: 1
   applications:
     iperf2:
       workloads: