Basic algorythm implemented

This commit is contained in:
Pünkösd Marcell 2021-12-13 02:38:10 +01:00
parent 2e8a4d25b4
commit ee28ef4637
2 changed files with 157 additions and 11 deletions

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#!/usr/bin/env python3
import kubernetes
def ensure_running_pod_on_site(site:str):
pass

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@ -4,23 +4,163 @@ from redis import Redis
import requests
from config import Config
from k8s_buzerator import ensure_running_pod_on_site
from urllib.parse import urljoin
RESCHEDULE_TIRGGER_LEVEL = 5 # how many times an incraising queue must be observed for an action to be taken
RESCHEDULE_TRIGGER_COUNTER_TTL = 60 # The counter clears itself after some time
RECENT_TROUBLE_TTL = 120 # how long a mark should live on a site which had trouble recently
def run(redis_client: Redis, site_url_map: Dict[str, str]):
run_count = redis_client.incr("RUNCOUNT")
logging.debug(f"Beginning of round {run_count}!")
# Get weather report
# get {http://example.com/report/}{site} The first part supplied
logging.debug("Getting performance reports...")
r = requests.get(urljoin(Config.COLLECTOR_URL, "site"), timeout=10)
r = requests.get(urljoin(Config.COLLECTOR_URL, "site"), timeout=30)
r.raise_for_status()
# TODO:
# - set the default scheduling site
# - Check if scheduling is required: any derivatives are above 0 for an extended period
# - if yes, then decide where to schedule
# - any sites with 0 derivative?
# - Check the k8s api before scheduling to see if the pod is running
# - check if there are any pod running where 0 units scheduled for extended time
# - delete that pod
# - write some log, so we can draw nice graphs
# Optional: check if a higher priority pod have free capacity, and move lower ones up
weather_report = r.json()
# Figuring out if any of the sites need attention
incraising_queue_at = []
for site_name, site_stat in weather_report:
if site_stat['queue']['derivative'] > 0.001 and site_stat['queue']['mean'] > 2:
key = f"INCRAISINGQUEUE:{site_name}"
incraising_queue_detected_times = redis_client.incr(key)
if incraising_queue_detected_times > RESCHEDULE_TIRGGER_LEVEL:
logging.debug(f"Tirgger level reached at {site_name}")
redis_client.delete(key)
incraising_queue_at.append(site_name)
else:
logging.debug(
f"Suspicious queue size change at {site_name} ({incraising_queue_detected_times}/{RESCHEDULE_TIRGGER_LEVEL})")
redis_client.expire(key, RESCHEDULE_TRIGGER_COUNTER_TTL) # Probably extend lifetime
# decide on default for the first time
if run_count > RESCHEDULE_TIRGGER_LEVEL * 2:
default_site = redis_client.get("DEFAULT:SCHEDULED")
if not default_site:
logging.debug("Default site is not set. Selecting one...")
for site in Config.SITE_LIST:
if site.name not in incraising_queue_at:
redis_client.set("DEFAULT:SCHEDULED", site)
logging.info(f"Default site set to {site}")
break
else:
logging.debug("Not enough data points to decide on default site yet")
# No sites need attention
if not incraising_queue_at:
logging.info("Everything seems to be in order. No incraising queues. Nothing to do")
return
# compile a list of where each client is scheduled
current_scheduling_table = {}
current_scheduling_table_counters = {}
logging.debug("State of scheduling right now:")
for key in redis_client.keys("SCHEDULED:*"):
target = redis_client.get(key)
if target:
target = target.decode('utf-8')
if target:
name = key[10:]
current_scheduling_table[name] = target
logging.debug(f"{name} -> {target}")
if target in current_scheduling_table_counters:
current_scheduling_table_counters[target] += 1
else:
current_scheduling_table_counters[target] = 1
logging.debug("Summary of scheduled clients:")
for site, counter in current_scheduling_table_counters.items():
logging.debug(f"{site}: {counter}")
if len(incraising_queue_at) == len(Config.SITE_LIST):
logging.warning("Out of resources! All sites reporting trouble, nowhere to reschedule!")
return
# If attention required, schedule a single workload to one tier lower
for site_seeking_attention in incraising_queue_at:
redis_client.set(f"RECENTTROUBLE:{site_seeking_attention}", b"\x01", ex=RECENT_TROUBLE_TTL)
if current_scheduling_table_counters[site_seeking_attention] == 0:
logging.warning("Wtf? Site reporting trouble, but there are no workload scheduled to it... nothing to do")
continue
logging.debug(f"Attempting to reschedule a single workload from {site_seeking_attention}...")
# Compile a list of sites with lower rank than the current one
lower_rank_sites = []
next_lower = True
for site in Config.SITE_LIST:
if next_lower:
lower_rank_sites.append(site)
else:
if site.name == site_seeking_attention:
next_lower = True
if not lower_rank_sites:
logging.warning("Out of lower rank sites! Nowhere to schedule! Giving up on this site.")
continue
# Select a fitting candidate from the lower rank sites
logging.debug(f"Selecting candidate out of these sites: {','.join(lower_rank_sites)}")
candidate = None
for lower_rank_site in lower_rank_sites:
logging.debug(f"Evaluating {lower_rank_site}")
recently_troubled = redis_client.get(f"RECENTTROUBLE:{lower_rank_site}")
if recently_troubled:
recently_troubled = recently_troubled.decode('utf-8')
if recently_troubled:
logging.debug(f"Site {lower_rank_site} had troubles recently, better not scheduling here...")
continue
if lower_rank_site in incraising_queue_at:
logging.debug(f"Site {lower_rank_site} is not a good candidate: It's currently reporting in trouble...")
continue
logging.debug(f"{lower_rank_site} seems to be an ideal candidate to move a single workload to")
candidate = lower_rank_site
break
if not candidate:
logging.warning("Could not find a good candidate to move a single workload to! Giving up!")
continue
# Do the actual re-scheduling
logging.debug(f"Re-scheduling a single workload from {site_seeking_attention} to {candidate}...")
ensure_running_pod_on_site(candidate) # blocking
# Choose a workload "randomly":
device_to_reschedule = None
for key in redis_client.keys("SCHEDULED:*"):
target = redis_client.get(key)
if target:
target = target.decode('utf-8')
if target == site_seeking_attention:
device_to_reschedule = key[10:]
break
if not device_to_reschedule:
logging.warning(f"No workload scheduled to {site_seeking_attention}... wtf??")
break
logging.info(f"Re-scheduling {device_to_reschedule} from {site_seeking_attention} to {candidate}")
redis_client.set(f"SCHEDULED:{device_to_reschedule}", candidate)
# Set the new site as default
current_default = redis_client.get("DEFAULT:SCHEDULED")
if not current_default or (current_default.decode('utf-8') == site_seeking_attention):
logging.info(f"Marking {candidate} as the new default site!")
redis_client.set("DEFAULT:SCHEDULED", candidate)