grafana loki query example

Line filter expressions support stripping ANSI sequences (color codes) from LogQL also supports a limited number of interval vector metric statements, similar to PromQL, with the following 4 functions. By default, a pattern expression is anchored at the start of the log line. Between two literals, the behavior is obvious: Adding EV Charger (100A) in secondary panel (100A) fed off main (200A). 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. The indent function indents every line in a given string to the specified indent width. Other elements are dropped. #This partial configuration uses IBM Cloud Object Storage (COS) for chunk storage. =~: regex matches. Signature: fromJson(v string) interface{}. You can use and and or to concatenate multiple predicates that represent and and or binary operations, respectively. Looking for job perks? line_format also supports math functions. Grafana Loki supports metric queries. Unwrapped ranges uses extracted labels as sample values instead of log lines. Loki indexes only the date, system name and a label for logs. Step One Install Grafana on an EC2 Instance Launch a t2.micro EC2 instance. Unlike the logfmt and json, which extract implicitly all values and takes no parameters, the regexp parser takes a single parameter | regexp "" which is the regular expression using the Golang RE2 syntax. For more information, refer to Add ad hoc filters. Multiple parsers can be used by a single log pipeline. Optionally, the log stream selector can be followed by a log pipeline. Only users with the organization administrator role can add data sources. This is specially useful when writing a regular expression which contains multiple backslashes that require escaping. For example, |json server_list="services", headers="request.headers will extract to the following tags. The Loki query editor helps you create log and metric queries that use Loki's query language, LogQL. For example, for the query {job="varlogs"}|json|drop level, method="GET", with below log line, Similary, this expression can be used to drop __error__ labels as well. 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. Open positions, Check out the open source projects we support They can be referenced using they label name prefixed by a . 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 . 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. 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 A Log Stream Selector determines how many logs will be searched for. The logfmt parser produces the duration and status_code labels, defines the field name example. 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. And you'll see this. 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. Share Improve this answer Follow answered Jan 29, 2022 at 10:25 Georgi Grafana Labs uses cookies for the normal operation of this website. More details can be found in the Golang language documentation. The result is propagated into the result vector with the grouping labels becoming the output label set. Signature: trimAll(chars string,src string) string. 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. 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. which will be then be available for further filtering and processing in subsequent expressions. Click on Select. To learn more, see our tips on writing great answers. discarding those lines that do not match the case-sensitive 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 last example will return Hello World. as it only does further processing when a line matches. =, =~, ! When using |~ and ! Inside string replacement, $ signs are interpreted as in Expand, so for instance $1 represents the text of the first sub-match. Additional helpful documentation, links, and articles: Scaling and securing your logs with Grafana Loki, Managing privacy in log data with Grafana Loki. We dont need most of the preceding log data, we just need to use <_> for placeholders, which is obviously much simpler than regular expressions. There are examples in Multiple parsers. with a value greater than 30 sections. 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 The line format expression can rewrite the log line content by using the text/template format. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. You can use a match-all regex together with a stream you have for all your logs. Can contain only one capture group. When you are. 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. See Matching IP addresses for details. The regex . The Loki data sources query editor helps you create log and metric queries that use Lokis query language, LogQL. Supported function for operating over unwrapped ranges are: Except for sum_over_time,absent_over_time, rate and rate_counter, unwrapped range aggregations support grouping. Grafana Labs uses cookies for the normal operation of this website. A log pipeline can be appended to a log stream selector to further process and filter log streams. For example with cluster="namespace" the cluster is the label identifier, the operation is = and the value is namespace. The above example means that all log streams with the tag app and the value mysql and the tag name and the value mysql-backup will be included in the query results. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. A query in Grafana, based on a Loki data source. To extract the method and the path of this logfmt log line. Sets the full link URL if the link is external, or a query for the target data source if the link is internal. . LogQL is Grafana Lokis PromQL-inspired query language. Divide numbers. 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 , For example, to extract servers fields as label, expression can be written as following, Note that | json servers is same as | json servers="servers". The __error__ label cant be renamed via the language. To avoid these problems, dont add labels until you know you need them. Is there a way to use inferred values in a regex based LOKI query? For example, use the json parser to extract the tags from the contents of the following files. as label_format; all expressions must be quoted. There are two types of LogQL queries: Log queries return the contents of log lines. The following example shows a full log query in action: {container="query-frontend",namespace="loki-dev"} |= "metrics.go" | logfmt | duration > 10s and throughput_mb < 500 The query is composed of: a log stream selector {container="query-frontend",namespace="loki-dev"} which targets the query-frontend container in the loki-dev namespace. If an expression filters out a log line, the pipeline will stop processing the current log line and start processing the next log line. Administrators can also configure the data source via YAML with Grafanas provisioning system. A predicate contains a tag identifier, operator and a value for comparing tags. A function is applied to aggregate the query over the duration. Loki supports the special Ad hoc filters variable type. 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 ""). The matching is case-sensitive by default. When both side are label identifiers, for example dst=src, the operation will rename the src label into dst. Log stream selectors are written by wrapping key-value pairs in a pair of curly brackets, e.g. In a chained pipeline, the result of each command is passed as the last argument of the following command. The renaming form dst=src will drop the src label after remapping it to the dst label. Use <_> at the beginning of the expression if you dont want to anchor the expression at the start. 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. {container="query-frontend",namespace="loki-dev"} |= "metrics.go" | logfmt | duration > 10s and throughput_mb < 500, POST /api/prom/api/v1/query_range (200) 1.5s, 0.191.12.2 - - [10/Jun/2021:09:14:29 +0000] "GET /api/plugins/versioncheck HTTP/1.1" 200 2 "-" "Go-http-client/2.0" "13.76.247.102, 34.120.177.193" "TLSv1.2" "US" "", - - <_> " <_>" <_> "" <_>, level=debug ts=2021-06-10T09:24:13.472094048Z caller=logging.go:66 traceID=0568b66ad2d9294c msg="POST /loki/api/v1/push (204) 16.652862ms", <_> msg=" () ", | duration >= 20ms or size == 20kb and method!~"2..", | duration >= 20ms or size == 20kb | method!~"2..", | duration >= 20ms or size == 20kb,method!~"2..", | duration >= 20ms or size == 20kb method!~"2..", | duration >= 20ms or method="GET" and size <= 20KB, | ((duration >= 20ms or method="GET") and size <= 20KB), | duration >= 20ms or (method="GET" and size <= 20KB), {container="frontend"} | logfmt | line_format "{{.query}} {{.duration}}", rate({filename="/var/log/nginx/access.log"}[5m])), count_over_time({filename="/var/log/message"} |~ "oom_kill_process" [5m])), sum(rate({filename="/var/log/nginx/access.log"}[5m])) by (pod), topk(5,sum(rate({filename="/var/log/nginx/access.log"}[5m])) by (pod))), sum(rate({app="foo", level="error"}[1m])) / sum(rate({app="foo"}[1m])), rate({app=~"foo|bar"}[1m]) and rate({app="bar"}[1m]), count_over_time({app="foo", level="error"}[5m]) > 10, {app="foo"} # anything that comes after will not be interpreted in your query, "This is a debug message. and is followed by 1 or more word characters. They evaluate to another literal that is the result of the operator applied to both scalar operands (1 + 1 = 2). Nested properties are flattened into label keys using the _ separator. 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. by and without are only used to group the input vector. 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. Here we illustrate monitoring Kubernetes events as an example. Of course, this means you need to have good label definition specifications on the log collection side. The string type works exactly the same way as the Prometheus tag matcher is used in the log stream selector, which means you can use the same operators (=, ! Returns a textual representation of the time value formatted according to the provided golang datetime layout. (They can only contain ASCII letters and digits, as well as underscores and colons. Metric queries cannot contain errors, in case errors are found during execution, Loki will return an error and appropriate status code. Each key is a log label and each value is that labels value. By default, the matching is case-sensitive and can be switched to be case-insensitive by prefixing the regular expression with (?i). Downloads. In this article, we will install Grafana, Loki and collect logs from . Go to that address and login with the username "admin" and password "admin". Now that the data in JSON is turned into log tags we can naturally use these tags to filter log data. What were the most popular text editors for MS-DOS in the 1980s? You can use double quoted string for the template or backticks `{{.label_name}}` to avoid the need to escape special characters. After parsing the log using the JSON parser, you can see that the Grafana-provided panel is differentiated using different colors depending on the value of level, and that the attributes of our log are now added to the Log tab. # A trusted profile will be used for authenticating with COS. We can either pass # the trusted profile name or trusted profile ID along with the compute resource token file. saada commented on Apr 8, 2022 edited A metric query for triggering the alert itself An optional log query to pass in to the message template such as { { $log := range .LogMessages }} rkonfj mentioned this issue on Dec 1, 2022 We use fluent-bit for logs processing from java application to kaffra (redpanda actually). This means if you need to remove errors from an unwrap expression it needs to be placed after the unwrap. The query looks as follows: {pod="loki-grafana-7d4d587544-npc6n"} Defines whether the link is internal or external. You can interpolate the value from the field with the. For example, the following is equivalent. *", with below log lines. The results are grouped by parent path. {host=~ ". IT admins should learn how the tool works, with log streams and a proprietary query language. Loki stores logs, they are all text, how do you calculate them? Signature: date(fmt string, date interface{}) string. You can forcefully override the original label using a label formatter expression. Querying and displaying log data from Loki is available via Explore and with the logs panel in visualizations. regexReplaceAllLiteral function returns a copy of the input string and replaces matches of the Regexp with the replacement string replacement. Queries act as if they are a distributed grep to aggregate log sources. The same rules that apply to the Prometheus tag selector also apply to the Loki log stream selector. Returns the number of nanoseconds elapsed since January 1, 1970 UTC. $1 is replaced with the first matching subgroup, Due to the design of Loki, all LogQL queries must contain a Log Stream selector. It searches the contents of the log line, If it matches, then the timeseries is returned with the label dst_label replaced by the expansion of replacement. The ignoring keyword causes specified labels to be ignored during matching. specified json fields to labels. I'm quite clear on what you want, but if you want to be alerted whenever a new log line appears for this stream, you might consider defining an alert expression like count_over_time ( {service="xxx", level="ERROR"} [1m]) > 0 aardvarkx1 October 12, 2021, 1:10pm 5 Ok, thank you. 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 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. While every query will have a stream selector, Connect and share knowledge within a single location that is structured and easy to search. Install Grafana Loki with Docker or Docker Compose, 0003: Query fairness across users within tenants. Use this function to trim just the prefix from a string. For example, lets consider the following NGINX log line data. NIntegrate failed to converge to prescribed accuracy after 9 \ recursive bisections in x near {x}. Calculate the number of times the kernel has experienced oom in the last 5 minutes. Asking for help, clarification, or responding to other answers. Return the smallest of a series of integers. In the case of an error, for example, if the line is not in the expected format, the log line will not be filtered but a new __error__ tag will be added. it is almost always better to have them at the beginning. Would you ever say "eat pig" instead of "eat pork"? Signature: round(a interface{}, p int, rOpt float64) float64, We can also provide a roundOn number as third parameter, With default roundOn of .5 the above value would be 123.88571, Signature: toFloat64(v interface{}) float64. For example, using the | unpack parser, you can get tags as follows. 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 Sorry, an error occurred. Signature: contains(s string, src string) bool. For details, refer to the query editor documentation. This function returns the current log line. Sorry, an error occurred. 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. Grafana Loki was introduced in 2018 as a lightweight and cost-effective log aggregation system inspired by Prometheus. Step 2: In Data Sources, you can search the source by name or type. 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. A complete query with a regular expression: Filter operators can be chained. The duration can be placed Signature: unixEpochMillis(date time.Time) string. A Log Stream represents log entries that have the same metadata (set of Labels). Any other queries to help debug would be appreciated! Decodes a JSON document into a structure. The | label_format expression can rename, modify or add labels. try to use static labels, the overhead is smaller, usually logs are injected into labels before they are sent to Loki, the recommended static labels contain. followed by text or a regular expression. )\\) (?P. Open positions, Check out the open source projects we support 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. You can take advantage of pipeline to join together multiple functions. Sorry, an error occurred. Signature: default(d string, src string) string. Generate points along line, specifying the origin of point generation in QGIS. Signature: func(a interface{}, v interface{}) float64, Mulitply numbers. In both cases above, if the target tag does not exist, then a new tag will be created. For example, to calculate the qps of nginx. 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. Return the largest of a series of floats: Signature: maxf(a interface{}, i interface{}) float64. Thanks for contributing an answer to Stack Overflow! Well demo all the highlights of the major release: new and updated visualizations and themes, data source improvements, and Enterprise features. What woodwind & brass instruments are most air efficient? Making statements based on opinion; back them up with references or personal experience. Defines a regular expression to evaluate on the log message and capture part of it as the value of the new field. The filter should be placed after the stage that generated this error. Sets the data source thats pre-selected for new panels. Sorry, an error occurred. 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. Curly braces ({ and }) delimit the stream selector. For more information about LogQL, see LogQL. The log stream selector determines which log streams should be included in your query results. Additional helpful documentation, links, and articles: Scaling and securing your logs with Grafana Loki, Managing privacy in log data with Grafana Loki. A stream may contain other pairs of labels and values, The |=, |~ and ! Open positions, Check out the open source projects we support Usually we do a comparison of thresholds after using interval vector calculations, which is useful for alerting, e.g. The replacement string is substituted directly, without using Expand. This will indent every line of text by 4 space characters and add a new line to the beginning. rev2023.4.21.43403. Log queries A log query consists of two parts: log stream selector, and a search expression. The only way to filter out errors is by using a label filter expressions. These links appear in the log details. Additional helpful documentation, links, and articles: Scaling and securing your logs with Grafana Loki, Managing privacy in log data with Grafana Loki.
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