The log lines will be extracted and rewritten to contain only query and the requested duration. Using Duration, Number and Bytes will convert the tag values before comparing and supports the following comparators. For internal links, you can select the target data source from a selector. You can use double-quoted strings or backquotes {{.label_name}} for templates to avoid escaping special characters. Which can be used to aggregate over distinct labels dimensions by including a without or by clause. Grafana Labs uses cookies for the normal operation of this website. For example the parser | regexp "(?P\\w+) (?P[\\w|/]+) \\((?P\\d+? The trim function removes space from either side of a string. See the golang Regexp.replaceAll documentation for more examples. Its easier to use the predefined parsers json and logfmt when you can. the query results It takes a comma-separated list of operations as arguments, and can perform multiple operations at once. Pay special attention to operator order when chaining arithmetic operators. A metric conversion for a label may fail. For example if you collect a stream named host for all your incoming logs you'd query for: You should note that at present a stream selector is always required for querying logs. with (?i). vector1 unless vector2 results in a vector consisting of the elements of vector1 for which there are no elements in vector2 with exactly matching label sets. |= "metrics.go" Return the per-second rate of all non-timeout errors Loki data source | Grafana documentation A Log Stream Selector determines how many logs will be searched for. Checks whether the string(src) is set, and returns default(d) if not set. A predicate contains a label identifier, an operation and a value to compare the label with. The renaming form dst=src will drop the src label after remapping it to the dst label. In Grafana Loki, the selected range of samples is a range of selected log or label values. Metric queries extend log queries by applying a function to log query results. How to Setup Grafana Loki for Free Log Management Each line filter expression has a filter operator Note: If you use Grafana Cloud, you can request modifications to this feature by opening a support ticket in the Cloud Portal. Each key is a log label and each value is that labels value. See vector aggregation examples for query examples that use vector aggregation expressions. by and without are only used to group the input vector. 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. Unify your data with Grafana plugins: Datadog, Splunk, MongoDB, and more. Signature: repeat(c int,value string) string. $2 with the second etc. Well demo all the highlights of the major release: new and updated visualizations and themes, data source improvements, and Enterprise features. Log line formatting expressions can be used to rewrite the contents of log lines by using Golangs text/template template format, which takes a string parameter | line_format "{{.label_name}}" as the template format, and all labels are variables injected into the template and can be used with the {.label_name }} notation to be used. Grafana refers to such variables as template variables. LogQL also supports a limited number of interval vector metric statements, similar to PromQL, with the following 4 functions. Grafana provides built-in support for Loki. Signature: trimSuffix(suffix string, src string) string. Downloads. developers don't need start one query from scratch It includes those log lines that contain a status_code label Only when using the bottomk and topk functions, we can enter the relevant arguments to the functions. 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. by does the opposite and drops labels that are not listed in the by clause, even if their label values are identical between all elements of the vector. If the expression returns an array or object, it will be assigned to the tag in json format. A log stream is a unique source of log content, such as a file. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. 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. 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. This means | label_format foo=bar,foo="new" is not allowed but you can use two expressions for the desired effect: | label_format foo=bar | label_format foo="new", Syntax: |drop name, other_name, some_name="some_value", The | drop expression will drop the given labels in the pipeline. If the bool modifier is provided, vector elements that would be dropped instead have the value 0 and vector elements that would be kept have the value 1. Learn more about Teams Decodes a JSON document into a structure. Signature: contains(s string, src string) bool. Label filters can be place anywhere in a log pipeline. Managing Grafana and Loki in a regulated multitenant environment A predicate contains a tag identifier, operator and a value for comparing tags. !=: not equal. They cannot start with a digit.). This is useful for parsing complex logs. Loki supports functions to operate on data. Extracted label keys are automatically sanitized by all parsers, to follow Prometheus metric name convention. 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. The = operator after the tag name is a tag matching operator, and there are several tag matching operators supported in LogQL. matches the regular expression regex against the label src_label. use LogQL syntax wisely to dramatically improve query efficiency. You can take advantage of pipeline to join together multiple functions. Supports multiple numbers. Loki - Amazon Managed Grafana The unwrap expression is noted | unwrap label_identifier where the label identifier is the label name to use for extracting sample values. to count error level log entries greater than 10 within 5 minutes. 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 Again, when results are not available, it enqueues the queries for downstream queriers to execute. Thanks for contributing an answer to Stack Overflow! For example, using | unpack with the log line: extracts the container and pod labels; it sets original log message as the new log line. to parse it further: Calculate the p99 of the nginx-ingress latency by path: Calculate the quantity of bytes processed per organization ID: Get the top 10 applications by the highest log throughput: Get the count of log lines for the last five minutes for a specified job, grouping The only way to filter out errors is by using a label filter expressions. Allows extracting container and pod tags and raw log messages as new log lines. Displayed as a label in the log details. Monitoring your docker container's logs the Loki way Use this function to remove given characters from the front or back of a string. When both side are label identifiers, for example dst=src, the operation will rename the src label into dst. Unwrapped ranges uses extracted labels as sample values instead of log lines. For instructions on how to add a data source to Grafana, refer to the administration documentation. From the Queries I've been executing nothing is returned. Install Grafana Loki with Docker or Docker Compose, 0003: Query fairness across users within tenants. as well as log lines that contain a duration label regexReplaceAll returns a copy of the input string, replacing matches of the Regexp with the replacement string replacement. 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. All log streams that have both a label of app whose value is mysql *)" will extract from the following line: The unpack parser parses a JSON log line, unpacking all embedded labels from Promtails pack stage. For example, the following log line data. The pattern parser is easier and faster to write; it also outperforms the regexp parser. 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. 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. This means that the labels passed to the log stream selector will affect the relative performance of the querys execution. Use interval and range variables This function returns the current log lines timestamp. The following query shows how you can reformat a log line to make it easier to read on screen. For example `\w+` is the same as "\\w+". For example, select pod and then select the loki-grafana pod to query all logs from this specific pod. Grafana Loki querying basics, log based metrics and setting - YouTube Between a vector and a scalar, these operators are applied to the value of every data sample in the vector, and vector elements between which the comparison result is false get dropped from the result vector. Collect and View Logs with Grafana Loki | by oleksii_y | Medium Note: By signing up, you agree to be emailed related product-level information. Which one to choose? 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. Use {host=~ ".+"} That should work always. Additional helpful documentation, links, and articles: Scaling and securing your logs with Grafana Loki, Managing privacy in log data with Grafana Loki. I don't know how to write this query. Install Grafana Loki with Docker or Docker Compose, 0003: Query fairness across users within tenants. What happened? It takes a single string parameter | line_format "{{.label_name}}", which is the template format. The hasPrefix and hasSuffix functions test whether a string has a given prefix or suffix. The result is propagated into the result vector with the grouping labels becoming the output label set. Monitoring with Grafana, Prometheus, and Loki - Medium Email update@grafana.com for help. And a label should only appear in one of the lists specified by on and group_x. What were the most popular text editors for MS-DOS in the 1980s? How to have multiple colors with a single material on a single object? Optionally, the log stream selector can be followed by a log pipeline. The Loki query editor helps you create log and metric queries that use Loki's query language, LogQL. How can i turn no data to zero in Loki - Grafana Loki - Grafana Labs For example the following template will output the value of the path label: Additionally you can also access the log line using the __line__ function and the timestamp using the __timestamp__ function. Subtract numbers. There are two types of LogQL queries: Log queries return the contents of log lines. For example, use the json parser to extract the tags from the contents of the following files. Metric queries | Grafana Loki documentationGetting Started with Grafana Loki, Part 1: The Concepts Each expression can filter out, parse, or mutate log lines and their respective labels. Nested properties are flattened into label keys using the _ separator. The = operator after the label name is a label matching operator. Keep log lines that have the substring error: Discard log lines that have the substring kafka.server:type=ReplicaManager: Keep log lines that contain a substring that starts with tsdb-ops and ends with io:2003. *"} doesn't work for me. followed by text or a regular expression. These links appear in the log details. 1-Local-Configuration-Example.yaml auth_enabled: false server: http_listen_port: 3100 common: ring: instance_addr: 127.0.0.1 kvstore: store: inmemory replication_factor: 1 path_prefix: /tmp/loki schema_config: configs: - from: 2020-05-15 store: boltdb-shipper object_store: filesystem schema: v11 index: prefix: index_ period: 24h Is there a generic term for these trajectories? Usage of Grafana Loki Query Language LogQL - SoByte ~, regular expressions with Golangs RE2 syntax can be used. I'm trying to test our Loki log data source. This complete query example will give results that include the string error, Of course, this means you need to have good label definition specifications on the log collection side. 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. Queries act as if they are a distributed grep to aggregate log sources. Using Loki based variable - Grafana Labs Community Forums 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. 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. You can use and and or to concatenate multiple predicates that represent and and or binary operations, respectively. You can use a match-all regex together with a stream you have for all your logs. The results are grouped by parent path. 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. This is the same template engine as the | line_format expression, which means labels are available as variables and you can use the same list of functions. configure caching, Loki can configure caching for multiple components, either redis or memcached, which can significantly improve performance. If start is >= 0 and end < 0 or end bigger than s length, this calls value[start:] A function is applied to aggregate the query over the duration. Here we deploy a sample application that is a fake logger with debug, info and warning logs output to stdout. After writing in the log stream selector, the resulting log data set can be further filtered using a search expression, which can be text or a regular expression, e.g. Lower this limit if your browser is sluggish when displaying logs in Explore. The ignoring keyword causes specified labels to be ignored during matching. An unnamed capture appears as <_>. The = operator after the label name is a label matching operator. For more information about LogQL, see LogQL. The new field with the link shown in log details: You can define and configure the data source in YAML files as part of Grafanas provisioning system. Line filter expressions have support matching IP addresses. Loki derived fields and correlation between logs and traces Grafana Loki balbersmann March 17, 2021, 8:43am #1 Hello, I want to correlate my Loki logs with my traces from Zipkin or Jaeger. 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 They can be referenced using they label name prefixed by a . For example, A capture is a field name delimited by the < and > characters. New navigation. Loki is installed using helm chart 3.8.0. The navigation in Grafana has been updated with a new design and an improved structure to make it easier for you to access the data you need. You can forcefully override the original label using a label formatter expression. See Unwrap examples for query examples that use the unwrap expression. A special property _entry will also be used to replace the original log line. Not the answer you're looking for? regexReplaceAllLiteral function returns a copy of the input string and replaces matches of the Regexp with the replacement string replacement. While every query will have a stream selector, LogQL queries can be annotated with the # character, 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). Inside string replacement, $ signs are interpreted as in Expand, so for instance $1 represents the text of the first sub-match. The indent function indents every line in a given string to the specified indent width. Click on Select. Set operations are only valid in the interval vector range, and currently support, LogQL supports the same comparison operators as PromQL, including. You can use a match-all regex together with a stream you have for all your logs. Install Grafana Loki with Docker or Docker Compose, 0003: Query fairness across users within tenants. 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+. 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. The log stream selector determines which log streams should be included in your query results. A minor scale definition: am I missing something? This topic explains configuring and querying specific to the Loki data source. 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. Log stream selectors are written by wrapping key-value pairs in a pair of curly brackets, e.g. Click on "Add data source" and search for Loki and Click on it. If the conversion of the tag value fails, the log line is not filtered and a __error__ tag is added. See Matching IP addresses for details. All LogQL queries contain a log stream selector. For example if you collect a stream named host for all your incoming logs you'd query for: {host=~ ". A complete query with a regular expression: Keep log lines that contain a substring that starts with error=, This will indent every line of text by 4 space characters and add a new line to the beginning. For example, the following is equivalent. The = operator after the tag name is a tag matching operator, and there are several tag matching operators supported in LogQL. Collect and Query your Kubernetes Cluster Logs with Grafana Loki The text template format used in | line_format and | label_format support the usage of functions. defines the field name example. 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 However if an extracted key appears twice, only the latest label value will be kept. If the regular expression doesnt match, The same rules that apply for Prometheus Label Selectors apply for Grafana Loki log stream selectors. which will be then be available for further filtering and processing in subsequent expressions. All matching elements in both vectors are dropped. and only include errors whose duration is above ten seconds. Now that the data in JSON is turned into log tags we can naturally use these tags to filter log data. 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. Is it still in development? The labels will be extracted as shown below. What differentiates living as mere roommates from living in a marriage-like relationship? and can be represented by commas, spaces, or other pipes, and tag filters can be placed anywhere in the log pipeline. The on keyword reduces the set of considered labels to a specified list. 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. For example, while the results are the same, the following query {job="mysql"} |= "error" |json | line_format "{{.err}}" will be faster than {job="mysql"} | json | line_format "{{.message}}" |= "error", Log line filter expressions are the fastest way to filter logs after log stream selectors . Generate points along line, specifying the origin of point generation in QGIS. Connect and share knowledge within a single location that is structured and easy to search. The string type is the only one that can filter out a log line with a label __error__. A query in Grafana, based on a Loki data source. For example, | json server_list="servers", headers="request.headers" will extract: If the label to be extracted is same as the original JSON field, expression can be written as just | json