ward off DDoS promql - Prometheus query check if value exist - Stack Overflow That's the query ( Counter metric): sum (increase (check_fail {app="monitor"} [20m])) by (reason) The result is a table of failure reason and its count. Please help improve it by filing issues or pull requests. what error message are you getting to show that theres a problem? By setting this limit on all our Prometheus servers we know that it will never scrape more time series than we have memory for. I am interested in creating a summary of each deployment, where that summary is based on the number of alerts that are present for each deployment. To learn more about our mission to help build a better Internet, start here. Is a PhD visitor considered as a visiting scholar? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Object, url:api/datasources/proxy/2/api/v1/query_range?query=wmi_logical_disk_free_bytes%7Binstance%3D~%22%22%2C%20volume%20!~%22HarddiskVolume.%2B%22%7D&start=1593750660&end=1593761460&step=20&timeout=60s, Powered by Discourse, best viewed with JavaScript enabled, 1 Node Exporter for Prometheus Dashboard EN 20201010 | Grafana Labs, https://grafana.com/grafana/dashboards/2129. This article covered a lot of ground. I believe it's the logic that it's written, but is there any . Both rules will produce new metrics named after the value of the record field. This is an example of a nested subquery. Using regular expressions, you could select time series only for jobs whose Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? The Linux Foundation has registered trademarks and uses trademarks. This is optional, but may be useful if you don't already have an APM, or would like to use our templates and sample queries. A metric is an observable property with some defined dimensions (labels). Each Prometheus is scraping a few hundred different applications, each running on a few hundred servers. You signed in with another tab or window. These checks are designed to ensure that we have enough capacity on all Prometheus servers to accommodate extra time series, if that change would result in extra time series being collected. privacy statement. Once theyre in TSDB its already too late. There is no equivalent functionality in a standard build of Prometheus, if any scrape produces some samples they will be appended to time series inside TSDB, creating new time series if needed. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. or Internet application, ward off DDoS Is a PhD visitor considered as a visiting scholar? The problem is that the table is also showing reasons that happened 0 times in the time frame and I don't want to display them. Cadvisors on every server provide container names. For example, this expression The most basic layer of protection that we deploy are scrape limits, which we enforce on all configured scrapes. to get notified when one of them is not mounted anymore. Other Prometheus components include a data model that stores the metrics, client libraries for instrumenting code, and PromQL for querying the metrics. Even i am facing the same issue Please help me on this. Explanation: Prometheus uses label matching in expressions. If you're looking for a or Internet application, Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? There are a number of options you can set in your scrape configuration block. What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? So lets start by looking at what cardinality means from Prometheus' perspective, when it can be a problem and some of the ways to deal with it. All they have to do is set it explicitly in their scrape configuration. Examples Here is the extract of the relevant options from Prometheus documentation: Setting all the label length related limits allows you to avoid a situation where extremely long label names or values end up taking too much memory. Basically our labels hash is used as a primary key inside TSDB. Its the chunk responsible for the most recent time range, including the time of our scrape. I then hide the original query. What does remote read means in Prometheus? notification_sender-. Prometheus lets you query data in two different modes: The Console tab allows you to evaluate a query expression at the current time. Under which circumstances? Creating new time series on the other hand is a lot more expensive - we need to allocate new memSeries instances with a copy of all labels and keep it in memory for at least an hour. list, which does not convey images, so screenshots etc. Looking to learn more? To learn more, see our tips on writing great answers. Once you cross the 200 time series mark, you should start thinking about your metrics more. This gives us confidence that we wont overload any Prometheus server after applying changes. Find centralized, trusted content and collaborate around the technologies you use most. Looking at memory usage of such Prometheus server we would see this pattern repeating over time: The important information here is that short lived time series are expensive. It would be easier if we could do this in the original query though. Every two hours Prometheus will persist chunks from memory onto the disk. We know what a metric, a sample and a time series is. You must define your metrics in your application, with names and labels that will allow you to work with resulting time series easily. result of a count() on a query that returns nothing should be 0 ? For example our errors_total metric, which we used in example before, might not be present at all until we start seeing some errors, and even then it might be just one or two errors that will be recorded. If so I'll need to figure out a way to pre-initialize the metric which may be difficult since the label values may not be known a priori. Can airtags be tracked from an iMac desktop, with no iPhone? instance_memory_usage_bytes: This shows the current memory used. help customers build privacy statement. Please open a new issue for related bugs. The more labels you have, or the longer the names and values are, the more memory it will use. This is in contrast to a metric without any dimensions, which always gets exposed as exactly one present series and is initialized to 0. When Prometheus sends an HTTP request to our application it will receive this response: This format and underlying data model are both covered extensively in Prometheus' own documentation. Return all time series with the metric http_requests_total: Return all time series with the metric http_requests_total and the given Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Show or hide query result depending on variable value in Grafana, Understanding the CPU Busy Prometheus query, Group Label value prefixes by Delimiter in Prometheus, Why time duration needs double dot for Prometheus but not for Victoria metrics, Using a Grafana Histogram with Prometheus Buckets. the problem you have. Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, How Intuit democratizes AI development across teams through reusability. This thread has been automatically locked since there has not been any recent activity after it was closed. Using a query that returns "no data points found" in an expression. In reality though this is as simple as trying to ensure your application doesnt use too many resources, like CPU or memory - you can achieve this by simply allocating less memory and doing fewer computations. To select all HTTP status codes except 4xx ones, you could run: Return the 5-minute rate of the http_requests_total metric for the past 30 minutes, with a resolution of 1 minute. In this blog post well cover some of the issues one might encounter when trying to collect many millions of time series per Prometheus instance. attacks, keep You can run a variety of PromQL queries to pull interesting and actionable metrics from your Kubernetes cluster. rev2023.3.3.43278. Sign up and get Kubernetes tips delivered straight to your inbox. Managed Service for Prometheus Cloud Monitoring Prometheus # ! This works well if errors that need to be handled are generic, for example Permission Denied: But if the error string contains some task specific information, for example the name of the file that our application didnt have access to, or a TCP connection error, then we might easily end up with high cardinality metrics this way: Once scraped all those time series will stay in memory for a minimum of one hour. For instance, the following query would return week-old data for all the time series with node_network_receive_bytes_total name: node_network_receive_bytes_total offset 7d information which you think might be helpful for someone else to understand Making statements based on opinion; back them up with references or personal experience. Prometheus simply counts how many samples are there in a scrape and if thats more than sample_limit allows it will fail the scrape. Do new devs get fired if they can't solve a certain bug? Separate metrics for total and failure will work as expected. It saves these metrics as time-series data, which is used to create visualizations and alerts for IT teams. Before running the query, create a Pod with the following specification: Before running the query, create a PersistentVolumeClaim with the following specification: This will get stuck in Pending state as we dont have a storageClass called manual" in our cluster. our free app that makes your Internet faster and safer. Variable of the type Query allows you to query Prometheus for a list of metrics, labels, or label values. or something like that. To get rid of such time series Prometheus will run head garbage collection (remember that Head is the structure holding all memSeries) right after writing a block. Name the nodes as Kubernetes Master and Kubernetes Worker. Is it a bug? The difference with standard Prometheus starts when a new sample is about to be appended, but TSDB already stores the maximum number of time series its allowed to have. Setting label_limit provides some cardinality protection, but even with just one label name and huge number of values we can see high cardinality. We know that time series will stay in memory for a while, even if they were scraped only once. attacks. binary operators to them and elements on both sides with the same label set I know prometheus has comparison operators but I wasn't able to apply them. If the error message youre getting (in a log file or on screen) can be quoted To subscribe to this RSS feed, copy and paste this URL into your RSS reader. If I now tack on a != 0 to the end of it, all zero values are filtered out: Thanks for contributing an answer to Stack Overflow! Having a working monitoring setup is a critical part of the work we do for our clients. The Graph tab allows you to graph a query expression over a specified range of time. The next layer of protection is checks that run in CI (Continuous Integration) when someone makes a pull request to add new or modify existing scrape configuration for their application. No Data is showing on Grafana Dashboard - Prometheus - Grafana Labs How Intuit democratizes AI development across teams through reusability. I suggest you experiment more with the queries as you learn, and build a library of queries you can use for future projects. Prometheus provides a functional query language called PromQL (Prometheus Query Language) that lets the user select and aggregate time series data in real time. How To Query Prometheus on Ubuntu 14.04 Part 1 - DigitalOcean count the number of running instances per application like this: This documentation is open-source. When time series disappear from applications and are no longer scraped they still stay in memory until all chunks are written to disk and garbage collection removes them. Prometheus's query language supports basic logical and arithmetic operators. more difficult for those people to help. Both of the representations below are different ways of exporting the same time series: Since everything is a label Prometheus can simply hash all labels using sha256 or any other algorithm to come up with a single ID that is unique for each time series.