基于Event Monitoring Database+Grafana的15分钟周期事件监控需求咨询

Hey there! Let's get your 15-minute event tracking sorted with Graphite + Grafana. From what you described, the issue is likely tied to how Carbon is storing/aggregating your data, or how you're querying it in Grafana. Let's walk through the fixes step by step:

First, Carbon needs explicit rules to know it should retain data in 15-minute intervals. Edit your storage-schemas.conf (usually located at /etc/carbon/ or /opt/graphite/conf/) and add a rule for your event metric:

[event_interview_counts]
pattern = ^events\.street_interview\.counts$
retentions = 15m:30d

• What this does: The pattern matches your metric name (adjust it to match whatever you're using, like events.street_interview.counts). The retentions line tells Carbon to keep one data point every 15 minutes, stored for 30 days (tweak the retention period to fit your needs).
• Don't forget to restart Carbon-Cache after saving:

  sudo systemctl restart carbon-cache
  

How you send data matters a lot. You have two options depending on your data collection workflow:

• Option 1: Send a total count per 15-minute window
  If you're already counting events in each 15-minute block, send the total count aligned to the end of the window. For example, in Python:

  import socket
  import time
  
  def send_to_graphite(metric, count):
      # Align timestamp to the end of the most recent 15-minute window (900 seconds)
      timestamp = int(time.time()) - (int(time.time()) % 900)
      message = f"{metric} {count} {timestamp}\n"
      with socket.socket() as sock:
          sock.connect(("your-graphite-ip", 2003))
          sock.sendall(message.encode())
  
  # Example: Send a count of 8 interviews from the last 15 minutes
  send_to_graphite("events.street_interview.counts", 8)
  

• Option 2: Send a "1" for every single event
  If you trigger a data send each time an event happens (like per interview), Carbon will need to sum these up over 15 minutes. Just make sure each send uses the current timestamp—Carbon will handle the aggregation later.

Now let's make sure Grafana displays the exact 15-minute counts you need:

• If you sent total counts per window: Simply query your metric directly (e.g., events.street_interview.counts). Grafana will automatically pick up the 15-minute interval from Carbon's schema.
• If you sent individual "1" events: Use the aggregateLine function to sum values over 15-minute windows. Your query would look like:

  aggregateLine(sum, events.street_interview.counts, 15m)
  

• Pro tip: In your Grafana panel settings, set the "Min interval" to 15m—this ensures the chart's X-axis uses 15-minute ticks, making it easier to read.

If you're seeing averages instead of total counts, check your storage-aggregation.conf to ensure Carbon uses the right aggregation method for your metric:

[event_interview_aggregation]
pattern = ^events\.street_interview\.counts$
aggregationMethod = sum
xFilesFactor = 0

• aggregationMethod = sum ensures Carbon adds up values when rolling up data.
• xFilesFactor = 0 tells Carbon to use 0 for any missing data points (so you don't get gaps if no events happened in a window).

• No data showing up? Check Carbon's logs (/var/log/carbon/carbon-cache.log) for errors. Test if the Carbon port is reachable with nc -zv your-graphite-ip 2003.
• Wrong counts? Verify your data sender is using the correct timestamp alignment (for windowed totals) or that your Grafana query is using sum instead of avg.

内容的提问来源于stack exchange，提问作者eramm