X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/4447b5a61f79edf2411ba94f4ad5d90e1ca7e220..2b2707e4acb9ee7eed53f573cf5365af9189a8e3:/lib/config/config.default.yml?ds=inline

diff --git a/lib/config/config.default.yml b/lib/config/config.default.yml
index 882ee62c35..b17523e356 100644
--- a/lib/config/config.default.yml
+++ b/lib/config/config.default.yml
@@ -992,6 +992,11 @@ Clusters:
       # disk cache size will use a disk cache, sized to the
       # container's RAM requirement (but with minimum 2 GiB and
       # maximum 32 GiB).
+      #
+      # Note: If you change this value, containers that used the previous
+      # default value will only be reused by container requests that
+      # explicitly specify the previous value in their keep_cache_ram
+      # runtime constraint.
       DefaultKeepCacheRAM: 0
 
       # Number of times a container can be unlocked before being
@@ -1055,16 +1060,6 @@ Clusters:
       # Container runtime: "docker" (default) or "singularity"
       RuntimeEngine: docker
 
-      # Number of "supervisor" containers eligible to run at any given
-      # time expressed as a fraction of CloudVMs.MaxInstances. A
-      # supervisor is a container who's purpose is to submit other
-      # containers, such as a container running arvados-cwl-runner.
-      # If there is a hard limit on the amount of concurrent
-      # containers that the cluster can run, it is important to avoid
-      # crowding out the containers doing useful work with containers
-      # who just create more work.
-      SupervisorFraction: 0.3
-
       # When running a container, run a dedicated keepstore process,
       # using the specified number of 64 MiB memory buffers per
       # allocated CPU core (VCPUs in the container's runtime
@@ -1339,6 +1334,21 @@ Clusters:
         # down.
         MaxInstances: 64
 
+        # Maximum fraction of CloudVMs.MaxInstances allowed to run
+        # "supervisor" containers at any given time. A supervisor is a
+        # container whose purpose is mainly to submit and manage other
+        # containers, such as arvados-cwl-runner workflow runner.
+        #
+        # If there is a hard limit on the amount of concurrent
+        # containers that the cluster can run, it is important to
+        # avoid crowding out the containers doing useful work with
+        # containers who just create more work.
+        #
+        # For example, with the default MaxInstances of 64, it will
+        # schedule at most floor(64*0.30) = 19 concurrent workflows,
+        # ensuring 45 slots are available for work.
+        SupervisorFraction: 0.30
+
         # Interval between cloud provider syncs/updates ("list all
         # instances").
         SyncInterval: 1m