For example, logfmt | duration > 1m and bytes_consumed > 20MB filters the expression. Loki - Amazon Managed Grafana Signature: func(a interface{}, v interface{}) int64, Signature: func(i interface{}) float64. Example of a query to print a - if the http_request_headers_x_forwarded_for label is empty: Counts occurrences of the regex (regex) in (src). Instead they are passed into the next stage of the pipeline with a new system label named __error__. Grafana Loki documentation LogQL: Log query language Query examples Open source Query examples These LogQL query examples have explanations of what the queries accomplish. The Settings tab of the data source is displayed. Signature: indent(spaces int,src string) string. and do not contain the string out of order. The Loki data sources query editor helps you create log and metric queries that use Lokis query language, LogQL. Signature: minf(a interface{}, i interface{}) float64, Returns the greatest float value greater than or equal to input value, Returns the greatest float value less than or equal to input value. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. You can use a tag formatting expression to force an override of the original tag, but if an extracted key appears twice, then only the latest tag value will be retained. You can see this data source is already present in Grafana. This example will return a vector with each time series having a foo label with the value a added to it: Sorry, an error occurred. Combined with parsers, metric queries can also be used to calculate metrics from a sample value within the log line, such as latency or request size. Adding EV Charger (100A) in secondary panel (100A) fed off main (200A). The regex . What was the actual cockpit layout and crew of the Mi-24A? developers don't need start one query from scratch Would you ever say "eat pig" instead of "eat pork"? = are filter operators that support the following. Open positions, Check out the open source projects we support Managing Grafana and Loki in a regulated multitenant environment Grafana Loki documentation LogQL: Log query language Template functions Open source Template functions The text template format used in | line_format and | label_format support the usage of functions. Signature: unixEpochNanos(date time.Time) string. For example, if we want to find the error rate inside a certain business log, we can calculate it as follows. A complete query with a regular expression: Keep log lines that contain a substring that starts with error=, =: exact match ! with any value other than the value 200, Connect Grafana to data sources, apps, and more, with Grafana Alerting, Grafana Incident, and Grafana OnCall, Frontend application observability web SDK, Try out and share prebuilt visualizations, Contribute to technical documentation provided by Grafana Labs, Help build the future of open source observability software label matchers (label matchers) are your first line of defense and are the best way to dramatically reduce the number of logs you search (for example, from 100TB to 1TB). Signature: min(a interface{}, i interface{}) int64. A label name can only appear once in each expression, which means that | label_format foo=bar,foo="new" is not allowed, but you can use two expressions to achieve the desired effect, such as | label_format foo=bar | label_format foo="new" . Unlike logfmt and json (which extract all values implicitly and without arguments), the regexp parser takes a single argument | regexp "" in the form of a regular expression using Golang RE2 syntax. Examples | Grafana Loki documentation For instance, the pipeline | json will produce the following mapping: In case of errors, for instance if the line is not in the expected format, the log line wont be filtered but instead will get a new __error__ label added. Unfortunately, I can't find an example / explanation which explains the procedure end-2-end (I have Grafana 7.4.0.) When you are. Example of a query to print how many times XYZ occurs in a line: Convert a humanized byte string to bytes using go-humanize, Convert a humanized time duration to seconds using time.ParseDuration, Signature: duration_seconds(string) float64. *"} doesn't work for me. It can contain multiple predicates. Is there a Loki query that returns all the logs? Getting Started with Grafana Loki - Geekflare The regular expression must contain a least one named sub-match (e.g (?Pre)), each sub-match will extract a different label. If the expression starts with literals, then the log line must also start with the same set of literals. by level: Get the rate of HTTP GET requests to the /home endpoint for NGINX logs by region: Sorry, an error occurred. of these in any level of nesting (my.list[0]["field"]). Add log message in alert Issue #5844 grafana/loki GitHub Inside string replacement, $ signs are interpreted as in Expand, so for instance $1 represents the text of the first sub-match. Note: By signing up, you agree to be emailed related product-level information. This will indent every line of text by 4 space characters and add a new line to the beginning. Use this function to repeat a string multiple times. Grafana Proxy deletes all other cookies. *"} You should note that at present a stream selector is always required for querying logs. without removes the listed labels from the result vector, while all other labels are preserved the output. For details, see the template variables documentation. with (?i). LogQL is Grafana Lokis PromQL-inspired query language. and a label of name whose value is mysql-backup will be included in Note: By signing up, you agree to be emailed related product-level information. Supports multiple numbers. For example, The log stream selector is specified by one or more comma-separated key-value pairs. Open positions, Check out the open source projects we support Log queries | Grafana Loki documentation This means that the . The results are grouped by parent path. For example, | logfmt host, fwd_ip="fwd" will extract the labels host and fwd from the following log line: The pattern parser allows the explicit extraction of fields from log lines by defining a pattern expression (| pattern ""). You can interpolate the value from the field with the. (e.g .label_name). The same rules that apply to the Prometheus tag selector also apply to the Loki log stream selector. The regular expression must contain at least one named submatch (e.g. and only include errors whose duration is above ten seconds. A function is applied to aggregate the query over the duration. However to select which label will be used within the aggregation, the log query must end with an unwrap expression and optionally a label filter expression to discard errors. The log stream selector determines which log streams should be included in your query results. For internal links, you can select the target data source from a selector. Open positions, Check out the open source projects we support Grafana Labs uses cookies for the normal operation of this website. Parses a formatted string and returns the time value it represents using the local timezone of the server running Loki. In both cases above, if the target tag does not exist, then a new tag will be created. The expression matches the structure of a log line. For example, to calculate the qps of nginx and group it by pod. How to Setup Grafana Loki for Free Log Management Signature: unixEpochMillis(date time.Time) string. Downloads. Example of a query to filter Loki querier jobs which create time is 1 day before: Returns the number of milliseconds elapsed since January 1, 1970 UTC. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Connect Grafana to data sources, apps, and more, with Grafana Alerting, Grafana Incident, and Grafana OnCall, Frontend application observability web SDK, Try out and share prebuilt visualizations, Contribute to technical documentation provided by Grafana Labs, Help build the future of open source observability software What are the advantages of running a power tool on 240 V vs 120 V? Use <_> at the beginning of the expression if you dont want to anchor the expression at the start. within the last minutes per host for the MySQL job, The labels will be extracted as shown below. For grouping tags, we can use without or by to distinguish them. Other static tags, such as environment, version, etc. Announcing Amazon Managed Grafana workspace version selection with Making statements based on opinion; back them up with references or personal experience. A complete query with a regular expression: Filter operators can be chained. Example of a query to print a newline per queries stored as a json array in the log line: Returns the current time in the local timezone of the Loki server. Query frontend caches and reuses them later if applicable. This is useful for parsing complex logs. Connect Grafana to data sources, apps, and more, with Grafana Alerting, Grafana Incident, and Grafana OnCall, Frontend application observability web SDK, Try out and share prebuilt visualizations, Contribute to technical documentation provided by Grafana Labs, Help build the future of open source observability software While log line filter expressions can be placed anywhere in the pipeline, it is best to place them at the beginning to improve the performance of the query and only do further follow-up when a line matches. In the official Loki Grafana documentation a pattern parser is mentioned: Grafana Labs LogQL LogQL: Log Query Language Loki comes with its own PromQL-inspired language for queries called LogQL. Metric queries extend log queries by applying a function to log query results. if a time series vector is multiplied by 2, the result is another vector in which every sample value of the original vector is multiplied by 2. A log pipeline can be attached to a log stream selector to further process and filter log streams. error level logs will be written to stderr and the actual log messages are generated in JSON format and a new log message will be created every 500 milliseconds. A log pipeline can be appended to a log stream selector to further process and filter log streams. This contrived query will return the intersection of these queries, effectively rate({app="bar"}): Comparison operators are defined between scalar/scalar, vector/scalar, and vector/vector value pairs. Connect Grafana to data sources, apps, and more, with Grafana Alerting, Grafana Incident, and Grafana OnCall, Frontend application observability web SDK, Try out and share prebuilt visualizations, Contribute to technical documentation provided by Grafana Labs, Help build the future of open source observability software Parser expressions parse and extract tags from log content, and these extracted tags can be used in tag filtering expressions for filtering, or for metric aggregation. include only those log lines that contain the string metrics.go Now that the data in JSON is turned into log tags we can naturally use these tags to filter log data. Sets the data source thats pre-selected for new panels. All labels are injected variables into the template and are available to use with the {{.label_name}} notation. These can significantly consume Lokis query performance. Collect and View Logs with Grafana Loki | by oleksii_y | Medium A log pipeline can consist of the following parts. Loki supports the special Ad hoc filters variable type. How to use Loki Pattern Parser - Grafana Labs Community Forums It's possible that the logs are in a different format to what I'm expecting, or that no Logs are ingested by Loki, and my pipeline is broken somewhere. Note: If you use Grafana Cloud, you can request modifications to this feature by opening a support ticket in the Cloud Portal. By default, a pattern expression is anchored at the start of the log line. Their behavior can be modified by providing bool after the operator, which will return 0 or 1 for the value rather than filtering. Grafana Labs uses cookies for the normal operation of this website. rev2023.4.21.43403. Add a link that uses the value of the field. For example, you can link to your tracing backend directly from your logs, or link to a user profile page if the log line contains a corresponding userId. Like PromQL, LogQL is filtered using tags and operators, and has two main types of query functions. For example, lets look at the following log line data. All labels are added as variables in the template engine. Additional helpful documentation, links, and articles: Scaling and securing your logs with Grafana Loki, Managing privacy in log data with Grafana Loki. For instructions on how to add a data source to Grafana, refer to the administration documentation. Between two scalars, these operators result in another scalar that is either 0 (false) or 1 (true), depending on the comparison result. I've looked through documentation, and so far, I haven't found any such Loki query. Checks whether the string(src) is set, and returns default(d) if not set. Group by regex Loki - Grafana Loki - Grafana Labs Community Forums Use this function to convert to lower case. $ ( '.custom-widget-menu-toggle, .toggle-menu-children' ).removeClass ( 'menu-opened' ); @ismail is currently assigned the tasks to bring it to parity and remove the old Grafana for querying and displaying the logs. Due to the design of Loki, all LogQL queries must contain a Log Stream selector. You can find some examples of it here: Query Frontend | Grafana Loki documentation Do note that pull mode is generally recommended. How about saving the world? Well demo all the highlights of the major release: new and updated visualizations and themes, data source improvements, and Enterprise features. Too many tag combinations can create a lot of streams, and it can make Loki store a lot of indexes and small chunks of object files. )\\) (?P. For example, |json server_list="services", headers="request.headers will extract to the following tags. New navigation. To extract the method and the path, Signature: unixEpoch(date time.Time) string. Email update@grafana.com for help. The renamed form dst=src will remove the src tag after remapping it to the dst tag, however, the template form will retain the referenced tag, for example dst="{{.src}}" results in both dst and src having the same value. vector1 or vector2 results in a vector that contains all original elements (label sets + values) of vector1 and additionally all elements of vector2 which do not have matching label sets in vector1. It typically consists of one or more expressions, each executed in turn for each log line. Collect and Query your Kubernetes Cluster Logs with Grafana Loki When both sides are label identifiers, for example dst=src, the operation will rename the src label to dst. The unpack parser will parse the json log lines and unpack all embedded tags through the packing phase, a special attribute _entry will also be used to replace the original log lines. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Once youve added the Loki data source, you can configure it so that your Grafana instances users can create queries in its query editor when they build dashboards, use Explore, and annotate visualizations. [Grafana Loki plugin] customize log query example in Kick start your The = operator after the tag name is a tag matching operator, and there are several tag matching operators supported in LogQL. To avoid escaping the featured character, you can use single quotes instead of double quotes when quoting a string, for example \w+1 is the same as \w+. They can be referenced using they label name prefixed by a . A metric conversion for a label may fail. Additional helpful documentation, links, and articles: Opening keynote: What's new in Grafana 9? Instead of hard-coding details such as server, application, and sensor names in metric queries, you can use variables. Parser expression can parse and extract labels from the log content. after the log stream selector or at end of the log pipeline. How a top-ranked engineering school reimagined CS curriculum (Ep. You can combine the unpack and json parsers (or any other parsers) if the original embedded log line is of a specific format. The query statement consists of the following parts. Click on "Add data source" and search for Loki and Click on it. For example, the parser | regexp "(?P\\w+) (?P[\\w|/]+) \\((?P\\\d+?) You must explicitly request matching by using the group_left or group_right modifier, where left or right determines which vector has the higher cardinality. The aggregation is applied over a time duration. In Grafana Loki, the selected range of samples is a range of selected log or label values. Hope you'll catch the bug", How to get the caller's function name, filename, and line number in a Go function, How to automatically set worker_processes for nginx containers, https://github.com/opsgenie/kubernetes-event-exporter/tree/master/deploy, https://grafana.com/grafana/dashboards/14003, Calculating relevant metrics in the log stream by filtering rules, If the log line is a valid json document, adding, Application name: kubernetes/labels/app_kubernetes_io/name. You can use double-quoted strings or backquotes {{.label_name}} for templates to avoid escaping special characters. Set operations are only valid in the interval vector range, and currently support, LogQL supports the same comparison operators as PromQL, including. A pattern expression is composed of captures and literals. A capture is a field name delimited by the < and > characters. Why in the Sierpiski Triangle is this set being used as the example for the OSC and not a more "natural"? A stream may contain other pairs of labels and values, For example, for the query {job="varlogs"}|json|drop __error__, with below log line, For the query {job="varlogs"}|json|drop level, path, app=~"some-api. Well demo all the highlights of the major release: new and updated visualizations and themes, data source improvements, and Enterprise features. If you want the regex dot character to match newlines you can use the single-line flag, like so: (?s)search_term.+ matches search_term\n. Loki supports two types of range vector aggregations: log range aggregations and unwrapped range aggregations. Count all the log lines within the last five minutes for the MySQL job. While line filter expressions could be placed anywhere within a log pipeline, This supports only tracing data sources. Parses a formatted string and returns the time value it represents in the provided timezone. It's not them. Loki supports two types of range vector aggregations: log range aggregations and unwrapped range aggregations. Each expression is executed in left to right sequence for each log line. We can also express this through a Boolean calculation, such as a statistic of error level log entries greater than 10 within 5 minutes is true. For example, if we want to filter logs with level=error, we just use the expression {app="fake-logger"} | json | level="error" to do so. All labels, including extracted ones, will be available for aggregations and generation of new series. Grafana Labs uses cookies for the normal operation of this website. The log lines will be extracted and rewritten to contain only query and the requested duration. LogQL also supports aggregation, which can be used to aggregate the elements within a single vector to produce a new vector with fewer elements. Use loki for log archiving. They evaluate to another literal that is the result of the operator applied to both scalar operands (1 + 1 = 2). On the top of the page, select Loki as your data source and then you can create a simple query by clicking on Log labels. Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey, Start and end parameters in query label_values (filename) loki, Collecting logs with fluentbit to loki - Indexing custom labels. To filters those errors see the pipeline errors section. Cheat Sheet - Loki - Seb's IT blog - GitLab Log range aggregations Metric queries cannot contain errors, in case errors are found during execution, Loki will return an error and appropriate status code. Share Improve this answer Follow answered Jan 29, 2022 at 10:25 Georgi This aggregation includes filters and parsers. topk and bottomk are different from other aggregators in that a subset of the input samples, including the original labels, are returned in the result vector. It takes a comma-separated list of operations as arguments, and can perform multiple operations at once. Refer to Googles RE2 syntax for more information. The = operator after the label name is a label matching operator. Use interval and range variables All log streams that have both a label of app whose value is mysql Line filter expressions are the fastest way to filter logs once the These links appear in the log details. {host=~ ". Metric queries | Grafana Loki documentation The capture of a pattern expression is a field name separated by the < and > characters, for example defines the field name as example, unnamed capture is displayed as <_>, and unnamed capture skips the match. The by clause does the opposite, dropping labels that are not listed in the clause, even if their label values are identical between all elements of the vector. The hasPrefix and hasSuffix functions test whether a string has a given prefix or suffix. Between two vectors, a binary arithmetic operator is applied to each entry in the left-hand side vector and its matching element in the right-hand vector. If a capture is not matched, the pattern parser will stop. You can use a debug section to see what your fields extract and how the URL is interpolated. The above query will give us the line as 1.1.1.1 200 3. Not the answer you're looking for? The trim function removes space from either side of a string. Filters are applied sequentially. Grafana, often with Prometheus, is a popular open source platform for monitoring and observability that can be used to query, visualize, and create alerts on a number of metric and data sources. Nested properties are flattened into label keys using the _ separator. Only field access (my.field, my["field"]) and array access (list[0]) are currently supported, as well as combinations of these in any level of nesting (my.list[0]["field"]). *)" will extract tags from the following lines. The without clause removes the listed labels from the resulting vector, keeping all others. This is specially useful when writing a regular expression which contains multiple backslashes that require escaping. This means that fewer tags lead to smaller indexes, which leads to better performance, so we should always think twice before adding tags. For multi-row LogQL queries, you can use # to exclude whole or partial rows. Query results will have satisfied every filter. Grafana Labs uses cookies for the normal operation of this website. loki is the main server, responsible for storing logs and processing queries. Label formatting is used to sanitize the query while the line format reduce the amount of information and creates a tabular output. This means that all the following expressions are equivalent: The precedence for evaluation of multiple predicates is left to right. It returns the per-second rate of all non-timeout errors within the last minutes per host for the MySQL job and only includes errors whose duration is above ten seconds. If an expression filters out a log line, the pipeline will stop processing the current log line and start processing the next log line. (?Pre)), with each submatch extracting a different tag. The right side can alternatively be a template string (double quoted or backtick), for example dst="{{.status}} {{.query}}", in which case the dst label value is replaced by the result of the text/template evaluation. Divide numbers. I created on my local pc, a Grafana container via Docker, with the help of docker-compose example from the Grafana official site: version: "3" networks: loki: services: loki: im. The stream selector determines which log streams to include in a querys results. The pattern parser is easier and faster to write; it also outperforms the regexp parser. If the expression returns an array or object, it will be assigned to the tag in json format. NIntegrate failed to converge to prescribed accuracy after 9 \ recursive bisections in x near {x}. The replacement string is substituted directly, without using Expand. Other elements are dropped. Sorry, an error occurred. Implement a health check with a simple query: Double the rate of a a log streams entries: Get proportion of warning logs to error logs for the foo app. ', referring to the nuclear power plant in Ignalina, mean? By default, the pattern expression is anchored at the beginning of the log line, and you can use <_> at the beginning of the expression to anchor the expression at the beginning. All labels are added as variables in the template engine. In addition, we can format the output logs according to our needs using line_format, for example, we use the query statement {app="fake-logger"} | json |is_even="true" | line_format "logs generated in {{.time}} on {{.level}}@ {{.pod}} Pod generated log {{.msg}}" to format the log output.