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query: with grafana gives inconsistent dashboard with every refresh

Open maartengo opened this issue 2 years ago • 18 comments

Thanos, Prometheus and Golang version used:

Object Storage Provider:

What happened: When using the Thanos querier as data source in Grafana, the dashboard data becomes inconsistent on every refresh. See gif for example. This doesn't happen if Grafana points directly to the Thanos sidecar. This is without usage of the storage gateway.

It might very well be a configuration issue, but we have no idea what could cause this.

Animation

What you expected to happen: Consistent data between refreshes

How to reproduce it (as minimally and precisely as possible): We haven't tried to reproduce this in a minimal setup, but it does happen on all of our environments (10+) all running the same configuration. I can supply the complete values.yaml privately if needed, but it boils down to:

thanos:
  storegateway:
    enabled: false
  query:
    enabled: true
    replicaLabel:
      - prometheus_replica
    dnsDiscovery:
      sidecarsService: 'prometheus-stack-kube-prom-thanos-discovery'
      sidecarsNamespace: 'prometheus'

kube-prometheus-stack:
  grafana:
    sidecar:
      datasources:
        url: http://prometheus-stack-thanos-query:9090/
        initDatasources: true
      dashboards:
        searchNamespace: ALL
        labelValue: null # Needs to be null in order to load our dashboards
  prometheus:
    replicas: 3
    thanosService:
      enabled: true
    thanosServiceMonitor:
      enabled: true
    service:
      sessionAffinity: 'ClientIP'
    prometheusSpec:
      thanos:
        objectStorageConfig:
          key: config-file.yaml
          name: thanos-secret

Chart:

  - name: kube-prometheus-stack
    version: 36.6.2
    repository: https://prometheus-community.github.io/helm-charts
  - name: thanos
    version: 10.5.5
    repository: https://charts.bitnami.com/bitnami

Full logs to relevant components:

  • Grafana: no logging occurs
  • Query: no logging occurs

Anything else we need to know:

Environment: K8S on AKS. First time deploying Thanos.

maartengo avatar Jul 14 '22 12:07 maartengo

Some things we tried:

  • Running one, or multiple instance of prometheus
  • Running one, or multiple instances of querier
  • Running without prometheus, only with data from storage gateway

We also noticed that the data shown in the Grafana dashboards is not necessarily inconsistent; it is data from the wrong graph/view from within the same dashboard. For example; a graph that should only have 0 and 1 values shows CPU values (0 - 100). It also looks like the data is mixed from multiple views instead of a simple switching.

maartengo avatar Jul 14 '22 14:07 maartengo

It's by design due to how deduplication works - in the beginning, we need to select one "true" series. Thanos uses a heuristic - it chooses the series with the most up-to-date information. So, on each refresh, you might get a different "true" series. The typical way to solve this is to have query-frontend in front which caches past results so they won't change on each refresh. Let me know if that helps.

GiedriusS avatar Jul 15 '22 06:07 GiedriusS

Unfortunately, we get the same effect with the query-frontend. The shown data keeps changing on refresh even when selecting a static time range. The results are good when viewing a single dashboard panel, but that was the case even before using the query-frontend

maartengo avatar Jul 15 '22 07:07 maartengo

@GiedriusS It's by design due to how deduplication works - in the beginning, we need to select one "true" series. Thanos uses a heuristic - it chooses the series with the most up-to-date information. So, on each refresh, you might get a different "true" series. The typical way to solve this is to have query-frontend in front which caches past results so they won't change on each refresh. Let me know if that helps.

Hi, what we seem to be seeing is that thanos-query is returning data for other panels/queries in the same dashboard in the same query result. We can usually plot the wrong graph on another panel in the same dashboard where it does make sense, and on refresh usually the graph moves to the correct panel.

If we inspect the query response we can see that data is contained in the result that does not make sense for the given query. For example, we have a query that should return 1 or 0. Among the 1's and 0's there are for some reason some time series with values like 1945. This should not be possible. If we execute the query standalone from the thanos-query UI the correct result is returned, but when executed from a grafana dashboard a mixed result is returned.

rouke-broersma avatar Jul 15 '22 07:07 rouke-broersma

I have removed grafana from the test. I tried to execute a bash script with multiple queries async and the data was scrambled again after a few attempts.

The bash script I used is below:

`curl 'http://prometheus-stack-thanos-query-frontend:9090/api/v1/query_range'
-H 'accept: application/json, text/plain, /'
-H 'Referer: '
-H 'content-type: application/x-www-form-urlencoded'
--data-raw 'query=mcps%3Akubelet_volume_stats_available%3Apercentage_mcps_workload%7BcustomerEnv%3D%22dev1%22%2CcustomerKey%3D%22ismcpsdev-dev3%22%7D&start=1657874085&end=1657877685&step=15'
--compressed > q1.json &

curl 'http://prometheus-stack-thanos-query-frontend:9090/api/v1/query_range'
-H 'accept: application/json, text/plain, /'
-H 'Referer: '
-H 'content-type: application/x-www-form-urlencoded'
--data-raw 'query=mcps%3Acontainer_resource_memory_usage%3Apercentage%7BcustomerEnv%3D%22dev1%22%2CcustomerKey%3D%22ismcpsdev-dev3%22%7D&start=1657874085&end=1657877685&step=15'
--compressed > q2.json &

curl 'http://prometheus-stack-thanos-query-frontend:9090/api/v1/query_range'
-H 'accept: application/json, text/plain, /'
-H 'Referer: '
-H 'content-type: application/x-www-form-urlencoded'
--data-raw 'query=mcps%3Acontainer_resource_cpu_usage%3Apercentage%7BcustomerEnv%3D%22dev1%22%2CcustomerKey%3D%22ismcpsdev-dev3%22%7D&start=1657874085&end=1657877685&step=15'
--compressed > q3.json &

curl 'http://prometheus-stack-thanos-query-frontend:9090/api/v1/query_range'
-H 'accept: application/json, text/plain, /'
-H 'Referer: '
-H 'content-type: application/x-www-form-urlencoded'
--data-raw 'query=mcps%3Anode_memory_pressure%3Atrue%7BcustomerEnv%3D%22dev1%22%2CcustomerKey%3D%22ismcpsdev-dev3%22%7D&start=1657874085&end=1657877685&step=15'
--compressed > q4.json &`

roelvdberg avatar Jul 15 '22 09:07 roelvdberg

We're seeing the same thing after upgrading Thanos from 0.24.0 to 0.27.0. Grafana 9.03 and Prometheus 2.32.1.

ddreier avatar Jul 15 '22 18:07 ddreier

Can confirm, saw the same issue using Grafana 9.0.3 with Thanos 0.27.0 + Prometheus 2.32.1.

UUIDNIE avatar Jul 15 '22 19:07 UUIDNIE

Is it still reproducible if you disable deduplication? 🤔

GiedriusS avatar Jul 16 '22 15:07 GiedriusS

This still happens even without deduplication

maartengo avatar Jul 18 '22 09:07 maartengo

Mhm, I see it now on my own Thanos cluster on some of the panels but it's still unclear to me what causes it or how to reproduce it consistently. Perhaps if any of you have some spare time, could you please try this with different versions between 0.24.0 & 0.27.0 to see when it starts occurring?

If it happens even with deduplication then https://github.com/thanos-io/thanos/commit/9a8c984144ddb320f60d5e0e30270ed03ad45c5c https://github.com/thanos-io/thanos/commit/d218e605c2dddab041551278bc1a5f632640f791 shouldn't cause it. :thinking:

Maybe https://github.com/thanos-io/thanos/commit/54a0deb98237e4474d6d3d0df70ea3d08869e859 is the culprit? Could you please try to see if reverting it helps? :thinking: However, my cluster doesn't have this commit yet so it must not be it.

GiedriusS avatar Jul 20 '22 13:07 GiedriusS

We've tested with 0.24.0, 0.25.0 and 0.26.0 they all don't seem to have the issue. It only starts occurring since 0.27.0.

rphua avatar Jul 22 '22 13:07 rphua

We saw the same behavior after upgrading from 0.25.2 to 0.27.0. Downgrading just the Querier to 0.26.0 resolved the issue.

In our case Grafana was receiving out of order samples and illogical results(results in billions when they should be in hundreds).

cuyoung avatar Jul 23 '22 18:07 cuyoung

We had gone back down to Thanos 0.24.0, but have since moved to 0.26.0 and are not having any problems.

ddreier avatar Jul 25 '22 19:07 ddreier

Another org checking in that has had to downgrade to 0.26. We upgraded to 0.27 and experienced some pretty wild values on our grafana dashboards (something that only reports 0 or 1 showing results in the thousands). Ended up here trying to find if anyone else was having the issue.

gwpries avatar Aug 03 '22 16:08 gwpries

Could you please try reverting https://github.com/thanos-io/thanos/pull/5410 and see if it helps? I'll try looking into this once I'll have some time.

GiedriusS avatar Aug 03 '22 18:08 GiedriusS

I also encountered this after upgrading from 0.26.0 to 0.27.0. Initially it appeared to only be present when using query frontend, but I later encountered it with just the plain querier. Also it's not specific to Grafana environments - I noticed the same weird data even when using the thanos query web UI.

dswarbrick avatar Aug 08 '22 11:08 dswarbrick

Was able to reproduce this by myself after updating. Reverting https://github.com/thanos-io/thanos/pull/5410 doesn't help, must be something more serious. Will try to reproduce locally && fix it. Must be some kind of race condition.

GiedriusS avatar Aug 10 '22 11:08 GiedriusS

Could you please try out main-2022-08-10-d00a713a or later and see if it helps?

GiedriusS avatar Aug 10 '22 19:08 GiedriusS

Can't reproduce this anymore with https://github.com/thanos-io/thanos/commit/d00a713a9bd66e650418bde6bd80ac7f2dc67428, will close this issue in a few days if nothing comes up.

GiedriusS avatar Aug 12 '22 06:08 GiedriusS

@yeya24 could you help release 0.27.1 for this important bug fix 😄

hanjm avatar Aug 19 '22 12:08 hanjm

@yeya24 could you help release 0.27.1 for this important bug fix 😄

cc @matej-g and @wiardvanrij

yeya24 avatar Aug 19 '22 17:08 yeya24

Having the same troubles. Please issue a patch release :)

Antiarchitect avatar Aug 23 '22 22:08 Antiarchitect

Still catching up, but https://github.com/thanos-io/thanos/releases/tag/v0.28.0 would be the fastest fix forward to get unblocked. I'll discuss if someone can make a patch

wiardvanrij avatar Aug 30 '22 14:08 wiardvanrij