Prefer reload to restart for HAProxy

The DFaaS agent restarts the HAProxy by issuing `systemctl restart
haproxy.service`, this causes a hard stop of the HAProxy, closing all
open connections and losing requests. The solution is to issue
`systemctl reload haproxy.service`, this will instruct HAProxy to do a
graceful stop when restarting. The latter will not close any open
connections and the restart mechanism without loss of requests is
automatically done by HAProxy in master-worker mode (the default on
Ubuntu).

Author: ema-pe

dfaasagent.env

@@ -20,7 +20,7 @@ AGENT_RECALC_PERIOD=1m
 AGENT_HAPROXY_TEMPLATE_FILE_NMS="/agent/haproxycfgnms.tmpl"
 AGENT_HAPROXY_TEMPLATE_FILE_RECALC="/agent/haproxycfgrecalc.tmpl"
 AGENT_HAPROXY_CONFIG_FILE="/etc/haproxy/haproxy.cfg"
-AGENT_HAPROXY_CONFIG_UPDATE_COMMAND="/usr/bin/systemctl restart haproxy.service"
+AGENT_HAPROXY_CONFIG_UPDATE_COMMAND="/usr/bin/systemctl reload haproxy.service"
 AGENT_HAPROXY_HOST=127.0.0.1
 AGENT_HAPROXY_PORT=80
 AGENT_HAPROXY_SOCK_PATH="unix:///run/haproxy/admin.sock"
@@ -47,4 +47,4 @@ AGENT_NODE_TYPE=1 # heavy=0 mid=1 light=2
 
 AGENT_NMS_CPU_THRESHOLD=120.0 # max cpu usage percentage
 AGENT_NMS_RAM_THRESHOLD=5500000000.0 # max ram usage in bytes
-AGENT_NMS_POWER_THRESHOLD=2100000.0 # max power usage in microwatts
+AGENT_NMS_POWER_THRESHOLD=2100000.0 # max power usage in microwatts

test_environment/dfaasagent-heavy.env

@@ -20,7 +20,7 @@ AGENT_RECALC_PERIOD=1m
 AGENT_HAPROXY_TEMPLATE_FILE_NMS="/agent/haproxycfgnms.tmpl"
 AGENT_HAPROXY_TEMPLATE_FILE_RECALC="/agent/haproxycfgrecalc.tmpl"
 AGENT_HAPROXY_CONFIG_FILE="/etc/haproxy/haproxy.cfg"
-AGENT_HAPROXY_CONFIG_UPDATE_COMMAND="/usr/bin/systemctl restart haproxy.service"
+AGENT_HAPROXY_CONFIG_UPDATE_COMMAND="/usr/bin/systemctl reload haproxy.service"
 AGENT_HAPROXY_HOST=172.16.238.12
 AGENT_HAPROXY_PORT=80
 AGENT_HAPROXY_SOCK_PATH="unix:///run/haproxy/admin.sock"
@@ -47,4 +47,4 @@ AGENT_NODE_TYPE=0 # heavy=0 mid=1 light=2
 
 AGENT_NMS_CPU_THRESHOLD=235.0 # max cpu usage percentage
 AGENT_NMS_RAM_THRESHOLD=6000000000.0 # max ram usage in bytes
-AGENT_NMS_POWER_THRESHOLD=3500000.0 # max power usage in microwatts
+AGENT_NMS_POWER_THRESHOLD=3500000.0 # max power usage in microwatts

test_environment/dfaasagent-light.env

@@ -20,7 +20,7 @@ AGENT_RECALC_PERIOD=1m
 AGENT_HAPROXY_TEMPLATE_FILE_NMS="/agent/haproxycfgnms.tmpl"
 AGENT_HAPROXY_TEMPLATE_FILE_RECALC="/agent/haproxycfgrecalc.tmpl"
 AGENT_HAPROXY_CONFIG_FILE="/etc/haproxy/haproxy.cfg"
-AGENT_HAPROXY_CONFIG_UPDATE_COMMAND="/usr/bin/systemctl restart haproxy.service"
+AGENT_HAPROXY_CONFIG_UPDATE_COMMAND="/usr/bin/systemctl reload haproxy.service"
 AGENT_HAPROXY_HOST=172.16.238.10
 AGENT_HAPROXY_PORT=80
 AGENT_HAPROXY_SOCK_PATH="unix:///run/haproxy/admin.sock"
@@ -47,4 +47,4 @@ AGENT_NODE_TYPE=2 # heavy=0 mid=1 light=2
 
 AGENT_NMS_CPU_THRESHOLD=104.0 # max cpu usage percentage
 AGENT_NMS_RAM_THRESHOLD=4100000000.0 # max ram usage in bytes
-AGENT_NMS_POWER_THRESHOLD=700000.0 # max power usage in microwatts
+AGENT_NMS_POWER_THRESHOLD=700000.0 # max power usage in microwatts

test_environment/dfaasagent-mid.env

@@ -20,7 +20,7 @@ AGENT_RECALC_PERIOD=1m
 AGENT_HAPROXY_TEMPLATE_FILE_NMS="/agent/haproxycfgnms.tmpl"
 AGENT_HAPROXY_TEMPLATE_FILE_RECALC="/agent/haproxycfgrecalc.tmpl"
 AGENT_HAPROXY_CONFIG_FILE="/etc/haproxy/haproxy.cfg"
-AGENT_HAPROXY_CONFIG_UPDATE_COMMAND="/usr/bin/systemctl restart haproxy.service"
+AGENT_HAPROXY_CONFIG_UPDATE_COMMAND="/usr/bin/systemctl reload haproxy.service"
 AGENT_HAPROXY_HOST=172.16.238.11
 AGENT_HAPROXY_PORT=80
 AGENT_HAPROXY_SOCK_PATH="unix:///run/haproxy/admin.sock"
@@ -47,4 +47,4 @@ AGENT_NODE_TYPE=1 # heavy=0 mid=1 light=2
 
 AGENT_NMS_CPU_THRESHOLD=190.0 # max cpu usage percentage
 AGENT_NMS_RAM_THRESHOLD=5500000000.0 # max ram usage in bytes
-AGENT_NMS_POWER_THRESHOLD=2100000.0 # max power usage in microwatts
+AGENT_NMS_POWER_THRESHOLD=2100000.0 # max power usage in microwatts