Use "requests" for CPU resources instead of limits

We now use a CPU request to ensure logging infrastructure pods are
not capped by default for CPU usage. It is still important to ensure
we have a minimum amount of CPU.

We keep the use of the variables *_cpu_limit so that the existing
behavior is maintained.

Note that we don't want to cap an infra pod's CPU usage by default,
since we want to be able to use the necessary resources to complete
it's tasks.

Bug 1501960 (https://bugzilla.redhat.com/show_bug.cgi?id=1501960)

3 files changed, 22 insertions, 11 deletions

diff --git a/roles/openshift_logging_mux/defaults/main.yml b/roles/openshift_logging_mux/defaults/main.yml
index 68412aec8..9de686576 100644
--- a/roles/openshift_logging_mux/defaults/main.yml
+++ b/roles/openshift_logging_mux/defaults/main.yml
@@ -9,10 +9,11 @@ openshift_logging_mux_namespace: logging
 
 ### Common settings
 openshift_logging_mux_nodeselector: "{{ openshift_hosted_logging_mux_nodeselector_label | default('') | map_from_pairs }}"
-openshift_logging_mux_cpu_limit: 500m
-openshift_logging_mux_memory_limit: 2Gi
-openshift_logging_mux_buffer_queue_limit: 1024
-openshift_logging_mux_buffer_size_limit: 1m
+openshift_logging_mux_cpu_limit: null
+openshift_logging_mux_cpu_request: 100m
+openshift_logging_mux_memory_limit: 512Mi
+openshift_logging_mux_buffer_queue_limit: 32
+openshift_logging_mux_buffer_size_limit: 8m
 
 openshift_logging_mux_replicas: 1
 
@@ -57,11 +58,11 @@ openshift_logging_mux_file_buffer_storage_type: "emptydir"
 openshift_logging_mux_file_buffer_pvc_name: "logging-mux-pvc"
 
 # required if the PVC does not already exist
-openshift_logging_mux_file_buffer_pvc_size: 4Gi
+openshift_logging_mux_file_buffer_pvc_size: 1Gi
 openshift_logging_mux_file_buffer_pvc_dynamic: false
 openshift_logging_mux_file_buffer_pvc_pv_selector: {}
 openshift_logging_mux_file_buffer_pvc_access_modes: ['ReadWriteOnce']
 openshift_logging_mux_file_buffer_storage_group: '65534'
 
 openshift_logging_mux_file_buffer_pvc_prefix: "logging-mux"
-openshift_logging_mux_file_buffer_limit: 2Gi
+openshift_logging_mux_file_buffer_limit: 256Mi
diff --git a/roles/openshift_logging_mux/tasks/main.yaml b/roles/openshift_logging_mux/tasks/main.yaml
index 2ec863afa..1b46a7ac3 100644
--- a/roles/openshift_logging_mux/tasks/main.yaml
+++ b/roles/openshift_logging_mux/tasks/main.yaml
@@ -171,6 +171,7 @@
     ops_host: "{{ openshift_logging_mux_ops_host }}"
     ops_port: "{{ openshift_logging_mux_ops_port }}"
     mux_cpu_limit: "{{ openshift_logging_mux_cpu_limit }}"
+    mux_cpu_request: "{{ openshift_logging_mux_cpu_request }}"
     mux_memory_limit: "{{ openshift_logging_mux_memory_limit }}"
     mux_replicas: "{{ openshift_logging_mux_replicas | default(1) }}"
     mux_node_selector: "{{ openshift_logging_mux_nodeselector | default({}) }}"
diff --git a/roles/openshift_logging_mux/templates/mux.j2 b/roles/openshift_logging_mux/templates/mux.j2
index 4cc48139f..7e88e3964 100644
--- a/roles/openshift_logging_mux/templates/mux.j2
+++ b/roles/openshift_logging_mux/templates/mux.j2
@@ -37,17 +37,26 @@ spec:
       - name: "mux"
         image: {{image}}
         imagePullPolicy: Always
-{% if (mux_memory_limit is defined and mux_memory_limit is not none) or (mux_cpu_limit is defined and mux_cpu_limit is not none) %}
+{% if (mux_memory_limit is defined and mux_memory_limit is not none) or (mux_cpu_limit is defined and mux_cpu_limit is not none) or (mux_cpu_request is defined and mux_cpu_request is not none) %}
         resources:
+{%   if (mux_memory_limit is defined and mux_memory_limit is not none) or (mux_cpu_limit is defined and mux_cpu_limit is not none) %}
           limits:
-{% if mux_cpu_limit is not none %}
+{%     if mux_cpu_limit is not none %}
             cpu: "{{mux_cpu_limit}}"
-{% endif %}
-{% if mux_memory_limit is not none %}
+{%     endif %}
+{%     if mux_memory_limit is not none %}
             memory: "{{mux_memory_limit}}"
+{%     endif %}
+{%   endif %}
+{%   if (mux_memory_limit is defined and mux_memory_limit is not none) or (mux_cpu_request is defined and mux_cpu_request is not none) %}
           requests:
+{%     if mux_cpu_request is not none %}
+            cpu: "{{mux_cpu_request}}"
+{%     endif %}
+{%     if mux_memory_limit is not none %}
             memory: "{{mux_memory_limit}}"
-{% endif %}
+{%     endif %}
+{%   endif %}
 {% endif %}
         ports:
         - containerPort: "{{ openshift_logging_mux_port }}"