will result in having the following labels extracted: Similar to JSON, using | logfmt label="expression", another="expression" in the pipeline will result in extracting only the fields specified by the labels. The left side can also be a template string, e.g. 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). LogQL uses labels and operators for filtering. This powerful feature creates metrics from logs. For example, to calculate the top 5 qps for nginx and group them by pod. Well demo all the highlights of the major release: new and updated visualizations and themes, data source improvements, and Enterprise features. Count all the log lines within the last five minutes for the traefik namespace. 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 The Derived Fields configuration helps you: 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. Step 3: Search by the name Loki. = are filter operators that support the following. This complete query example will give results that include the string error, If the original embedded log lines are in a specific format, you can use unpack in combination with a json parser (or other parser). To filters those errors see the pipeline errors section. Since label values are string, by default a conversion into a float (64bits) will be attempted, in case of failure the __error__ label is added to the sample. This means that the . You can use double-quoted strings or backquotes {{.label_name}} for templates to avoid escaping special characters. Signature: count(regex string, src string) int. 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. After parsing, these attributes can be extracted as follows. The regular expression must contain a least one named sub-match (e.g (?Pre)), each sub-match will extract a different label. Metric queries can be used to calculate the rate of error messages or the top N log sources with the greatest quantity of logs over the last 3 hours. In both cases above, if the target tag does not exist, then a new tag will be created. Set the data sources basic configuration options: Note: To troubleshoot configuration and other issues, check the log file located at /var/log/grafana/grafana.log on Unix systems, or in /data/log on other platforms and manual installations. They can be referenced using they label name prefixed by a . They evaluate to another literal that is the result of the operator applied to both scalar operands (1 + 1 = 2). 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. Would you ever say "eat pig" instead of "eat pork"? 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 Parses a formatted string and returns the time value it represents in the provided timezone. In this example, log streams that have a label of app whose value is mysql and a label of name whose value is mysql-backup will be included in the query results. You can use a match-all regex together with a stream you have for all your logs. If the expression starts with literals, then the log line must also start with the same set of literals. A log pipeline is a set of stage expressions that are chained together and applied to the selected log streams. Divide numbers. Email update@grafana.com for help. Log queries A log query consists of two parts: log stream selector, and a search expression. Line filter expressions have support matching IP addresses. 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. Unfortunately, I can't find an example / explanation which explains the procedure end-2-end (I have Grafana 7.4.0.) The string type is the only one that can filter out a log line with a label __error__. use multiple parsers (logfmt and regexp): This is possible because the | line_format reformats the log line to become POST /api/prom/api/v1/query_range (200) 1.5s which can then be parsed with the | regexp parser. Sorry, an error occurred. A log stream is a unique source of log content, such as a file. Signature: trimPrefix(prefix string, src string) string. Label filter expressions have support matching IP addresses. You can interpolate the value from the field with the. Is there a generic term for these trajectories? Subtract numbers. 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. Hi, @owen-d, @cyriltovena, I'm trying to do something that is new to me with a loki query to make up a dashboard. There are two types of LogQL queries: Log queries return the contents of log lines. 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. Return the per-second rate of all non-timeout errors The text template format used in | line_format and | label_format support the usage of functions. For example the json parsers will extract from the following document: Using | json label="expression", another="expression" in your pipeline will extract only the Each key is a log label and each value is that labels value. grafana memory usage query Metric queries extend log queries by applying a function to log query results. Literals can be any sequence of UTF-8 characters, including whitespace characters. Q&A for work. This version uses group_left() to include from the right hand side in the result and returns the cost of discarded events per user, organization, and namespace: LogQL queries can be commented using the # character: With multi-line LogQL queries, the query parser can exclude whole or partial lines using #: There are multiple reasons which cause pipeline processing errors, such as: When those failures happen, Loki wont filter out those log lines. How to Setup Grafana Loki for Free Log Management Queries act as if they are a distributed grep to aggregate log sources. String type work exactly like Prometheus label matchers use in log stream selector. A log range aggregation is a query followed by a duration. Which ability is most related to insanity: Wisdom, Charisma, Constitution, or Intelligence? All of the following expressions are equivalent: By default, multiple predicates are prioritized from right to left. Alternatively, you can use the \s (match whitespaces, including newline) in combination with \S (match not whitespace characters) to match all characters, including newlines. The filter should be placed after the stage that generated this error. Use the following command to create the sample application. Loki supports functions to operate on data. I used a Grafana transformation which seems to work Add field from calculation Binary operation Select the query and do + 0 I then hide the original query It would be easier if we could do this in the original query though 1 Like waterdrop01 September 28, 2021, 3:39pm #9 Agreed! For example `\w+` is the same as "\\w+". Getting Started with Grafana Loki - Geekflare Using Duration, Number and Bytes will convert the tag values before comparing and supports the following comparators. Supports multiple numbers. Step 1: Go to Grafana Configurations and Click on "Data Sources". Inspired by PromQL, Loki also has its own query language, called LogQL, which is like a distributed grep that aggregates views of logs. 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. The parsers json, logfmt, pattern, regexp and unpack are currently supported. Install Grafana Loki with Docker or Docker Compose, 0003: Query fairness across users within tenants. Example: If we have the following labels ip=1.1.1.1, status=200 and duration=3000(ms), we can divide the duration by 1000 to get the value in seconds. Switch to case-insensitive matching by prefixing the regular expression Sorry, an error occurred. Signature: repeat(c int,value string) string. The log stream selector is optionally followed by a log pipeline for further processing and filtering of log stream information, which consists of a set of expressions, each of which performs relevant filtering for each log line in left-to-right order, each of which can filter, parse and change the log line content and its respective label. An example that mutates is the expression. loki is the main server, responsible for storing logs and processing queries. Signature: min(a interface{}, i interface{}) int64. defines the field name example. The regular expression must contain at least one named submatch (e.g. Usually we do a comparison of thresholds after using interval vector calculations, which is useful for alerting, e.g. Like PromQL, LogQL is filtered using tags and operators, and has two main types of query functions. The only way to filter out errors is by using a label filter expressions. Some expressions can mutate the log content and respective labels, Signature: indent(spaces int,src string) string. Thanks for contributing an answer to Stack Overflow! However if an extracted key appears twice, only the latest label value will be kept. A more granular log stream selector then reduces the number of searched streams to a manageable volume. of these in any level of nesting (my.list[0]["field"]). See vector aggregation examples for query examples that use vector aggregation expressions. =~: regex matches. If the conversion of the label value fails, the log line is not filtered and an __error__ label is added. You can wrap predicates with parenthesis to force a different precedence. For details, refer to the query editor documentation. Vector elements for which the expression is not true or which do not find a match on the other side of the expression get dropped from the result, while the others are propagated into a result vector. Email update@grafana.com for help. By default, the matching is case-sensitive and can be switched to be case-insensitive by prefixing the regular expression with (?i). The results are grouped by parent path. For example, logfmt | duration > 1m and bytes_consumed > 20MB filters the expression. 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. The log stream selector determines which log streams should be included in your query results. log stream selectors have been applied. 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. If a capture is not matched, the pattern parser will stop. If an extracted label key name already exists in the original log stream, the extracted label key will be suffixed with the _extracted keyword to make the distinction between the two labels. For example, given these fake logs: GET /foo/bar GET /foo/baz GET /quux/ GET /foo GET /baz The query statement consists of the following parts. Using basic authorization and a derived field: You must escape the dollar ($) character in YAML values because it can be used to interpolate environment variables: In this example, the Jaeger data sources uid value should match the Loki data sources datasourceUid value. =: exact match ! Refer to Googles RE2 syntax for more information. From the Queries I've been executing nothing is returned. You can use this variable type to specify any number of key/value filters, and Grafana applies them automatically to all of your Loki queries. LogQL: Log query language LogQL is Grafana Loki's PromQL-inspired query language. For more information, refer to Add ad hoc filters. You can use a debug section to see what your fields extract and how the URL is interpolated. Open the Loki query editor. Use this function to convert to lower case. and is followed by 1 or more word characters. By default they filter. Between two scalars, these operators result in another scalar that is either 0 (false) or 1 (true), depending on the comparison result. Signature: unixEpochMillis(date time.Time) string. In a chained pipeline, the result of each command is passed as the last argument of the following command. Signature: trimSuffix(suffix string, src string) string. It can contain multiple predicates. Install Grafana Loki with Docker or Docker Compose, 0003: Query fairness across users within tenants. regexReplaceAllLiteral function returns a copy of the input string and replaces matches of the Regexp with the replacement string replacement. it is almost always better to have them at the beginning. Defines whether the link is internal or external. This topic explains configuring and querying specific to the Loki data source. Supports multiple numbers. --> Fixes #25205 **Special notes for your reviewer**: Note: If you use Grafana Cloud, you can request modifications to this feature by opening a support ticket in the Cloud Portal. For more consistency between Loki installations, its recommended to use toDateInZone, The format string must use the exact date as defined in the golang datetime layout, Signature: toDate(fmt, str string) time.Time. What woodwind & brass instruments are most air efficient? Note: By signing up, you agree to be emailed related product-level information. Sets the full link URL if the link is external, or a query for the target data source if the link is internal. 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. #This partial configuration uses IBM Cloud Object Storage (COS) for chunk storage. Why in the Sierpiski Triangle is this set being used as the example for the OSC and not a more "natural"? These links appear in the log details. rev2023.4.21.43403. Grafana Loki supports metric queries. Can contain only one capture group. A tag filter expression allows to filter log lines using their original and extracted tags, and it can contain multiple predicates. the query results. Defines which cookies are forwarded to the data source. We dont need most of the preceding log data, we just need to use <_> for placeholders, which is obviously much simpler than regular expressions. Use this function to convert to upper case. =, =~, ! Loki Ruler not sending alerts to alert Manager, How to visualize Loki JSON logs in Grafana. Curly braces ({ and }) delimit the stream selector. What were the most popular text editors for MS-DOS in the 1980s? Grafana Loki, a log processing tool, is designed to work at high speeds and large scale, on the minimum possible resources. Log line filtering expressions are used to perform a distributed grep on aggregated logs in a matching log stream. Loki indexes only the date, system name and a label for logs. Setting -store.max-look-back-period=168h limits loki search to 7days but there is no way to query old logs (using athena for example). 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. Downloads. Consider this logfmt log line. A capture is a field name delimited by the < and > characters. Which one to choose? A stream may contain other pairs of labels and values, By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. See Matching IP addresses for details. By default, the system matches and, unless, and or operations with all entries in the right vector. Optionally the label identifier can be wrapped by a conversion function | unwrap (label_identifier), which will attempt to convert the label value from a specific format. Why? Is there a way to use inferred values in a regex based LOKI query? A predicate contains a label identifier, an operation and a value to compare the label with. `label_values({compose_service=~$service, compose_project=~$project}, container_name)` **Which issue(s) this PR fixes**: - Automatically closes linked issue when the Pull Request is merged. Click on Select. When you are. order the filtering stages left to right: Within this query, the stream selector is. Returns the number of seconds elapsed since January 1, 1970 UTC. 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. Grafana Loki was introduced in 2018 as a lightweight and cost-effective log aggregation system inspired by Prometheus. An unnamed capture appears as <_>. which will be then be available for further filtering and processing in subsequent expressions. The selector consists of one or more key-value pairs, where each key is a log tag and each value is the value of that tag. Entries for which no matching entry in the right-hand vector can be found are not part of the result. Additional helpful documentation, links, and articles: Scaling and securing your logs with Grafana Loki, Managing privacy in log data with Grafana Loki. Grafana Labs uses cookies for the normal operation of this website. Adding EV Charger (100A) in secondary panel (100A) fed off main (200A). This supports only tracing data sources. The logfmt parser can be added by using | logfmt, which will advance all the keys and values from the logfmt formatted log lines. You can take advantage of pipeline to join together multiple functions. The filter operators can be chained and will filter expressions in order, and the resulting log lines must satisfy each filter. The following binary arithmetic operators exist in Loki: Binary arithmetic operators are defined between two literals (scalars), a literal and a vector, and two vectors. LogQL supports a variety of value types that are automatically inferred from the query input. Between two literals, the behavior is obvious: Multiple parsers can be used by a single log pipeline. Return log lines that are not within a range of IPv4 addresses: This example matches log lines with all IPv4 subnet values 192.168.4.5/16 except IP address 192.168.4.2: Extract the user and IP address of failed logins from Linux /var/log/secure, Get successful logins from Linux /var/log/secure. without removes the listed labels from the result vector, while all other labels are preserved the output. And you'll see this. 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. to count error level log entries greater than 10 within 5 minutes. Add log message in alert Issue #5844 grafana/loki GitHub Here we deploy a sample application that is a fake logger with debug, info and warning logs output to stdout. Connect and share knowledge within a single location that is structured and easy to search. Loki supports two types of range vector aggregations: log range aggregations and unwrapped range aggregations. Inside string replacement, $ signs are interpreted as in Expand, so for instance $1 represents the text of the first sub-match. These logical/set binary operators are only defined between two vectors: vector1 and vector2 results in a vector consisting of the elements of vector1 for which there are elements in vector2 with exactly matching label sets. Lokis strength lies in parallel querying, using filter expressions (label=text, |~ regex, ) to query the logs will be more efficient and fast. Use loki for log archiving. Instead they are passed into the next stage of the pipeline with a new system label named __error__. Not the answer you're looking for? Signature: fromJson(v string) interface{}. Return the smallest of a series of floats. followed by text or a regular expression. Generate points along line, specifying the origin of point generation in QGIS. These LogQL query examples have explanations of what the queries accomplish. Again, when results are not available, it enqueues the queries for downstream queriers to execute. Log range aggregations The syntax: The label list provided with the group modifier contains additional labels from the one-side that are included in the result metrics. Open positions, Check out the open source projects we support You can wrap predicates in parentheses to force a different priority from left to right. character does not match newlines by default. This means that all the following expressions are equivalent: The precedence for evaluation of multiple predicates is left to right. *)" will extract tags from the following lines. *)" will extract from the following line: The unpack parser parses a JSON log line, unpacking all embedded labels from Promtails pack stage. LogQL also supports metrics for log streams as a function, typically we can use it to calculate the error rate of messages or to sort the application log output Top N over time. Teams. The pattern parser allows fields to be extracted explicitly from log lines by defining a pattern expression (| pattern "") that matches the structure of the log line. Python script that identifies the country code of a given IP address. Obviously the mathematical operations in LogQL are oriented towards interval vector operations, and the supported binary operators in LogQL are as follows. over the aggregated logs from the matching log streams. The same rules that apply to the Prometheus tag selector also apply to the Loki log stream selector. Email update@grafana.com for help. Using Duration, Number and Bytes will convert the label value prior to comparision and support the following comparators: For instance, logfmt | duration > 1m and bytes_consumed > 20MB. Note: By signing up, you agree to be emailed related product-level information. The pattern parser is easier and faster to write; it also outperforms the regexp parser. On the other hand, Grafana Loki can be run smoothly on a relatively small server. First you need to install [kubernetes-event-exporter] at https://github.com/opsgenie/kubernetes-event-exporter/tree/master/deploy and the kubernetes-event- exporter logs will be printed to stdout, and then our promtail will upload the logs to Loki. We use loki to ingest and query logs from different AWS services. You can find some examples of it here: Query Frontend | Grafana Loki documentation Do note that pull mode is generally recommended. If the bool modifier is provided, vector elements that would have been dropped instead have the value 0 and vector elements that would be kept have the value 1, with the grouping labels again becoming the output label set. This means that the regex expression must match against the entire string, including newlines. What was the actual cockpit layout and crew of the Mi-24A? Return the smallest of a series of integers. $1 is replaced with the first matching subgroup, Grouping modifiers can only be used for comparison and arithmetic. Collect and View Logs with Grafana Loki | by oleksii_y | Medium *", with below log lines. Grafana Proxy deletes all other cookies. Open positions, Check out the open source projects we support The = operator after the tag name is a tag matching operator, and there are several tag matching operators supported in LogQL. [Grafana Loki plugin] customize log query example in Kick start your Sets the HTTP protocol, IP, and port of your Loki instance, such as. 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.
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