zipkin-server

zipkin-server

zipkin-server is a Spring Boot application, packaged as an executable jar. You need JRE 8+ to start zipkin-server.

Span storage and collectors are configurable. By default, storage is in-memory, the http collector (POST /api/v2/spans endpoint) is enabled, and the server listens on port 9411.

Quick-start

The quickest way to get started is to fetch the latest released server as a self-contained executable jar. Note that the Zipkin server requires minimum JRE 8. For example:

$ curl -sSL https://zipkin.io/quickstart.sh | bash -s
$ java -jar zipkin.jar

Once you've started, browse to http://your_host:9411 to find traces!

Endpoints

The following endpoints are defined under the base url http://your_host:9411

• / - UI
• /config.json - Configuration for the UI
• /api/v2 - Api
• /health - Returns 200 status if OK
• /info - Provides the version of the running instance
• /metrics - Includes collector metrics broken down by transport type

There are more built-in endpoints provided by Spring Boot, such as /metrics. To comprehensively list endpoints, GET /mappings.

The legacy /api/v1 Api is still supported. Backends are decoupled from the HTTP api via data conversion. This means you can still accept legacy data on new backends and visa versa. Enter https://zipkin.io/zipkin-api/zipkin-api.yaml into the explore box of the Swagger UI to view the old definition

CORS (Cross-origin Resource Sharing)

By default, all endpoints under /api/v2 are configured to allow cross-origin requests.

This can be changed by modifying the YAML configuration file (zipkin.query.allowed-origins) or by setting an environment variable.

For example, to allow CORS requests from http://foo.bar.com:

ZIPKIN_QUERY_ALLOWED_ORIGINS=http://foo.bar.com

Logging

By default, zipkin writes log messages to the console at INFO level and above. You can adjust categories using the --logging.level.XXX parameter, a -Dlogging.level.XXX system property, or by adjusting yaml configuration.

For example, if you want to enable debug logging for all zipkin categories, you can start the server like so:

$ java -jar zipkin.jar --logging.level.zipkin2=DEBUG

Under the covers, the server uses Spring Boot - Logback integration. For example, you can add --logging.exception-conversion-word=%wEx{full} to dump full stack traces instead of truncated ones.

Metrics

Metrics are exported to the path /metrics and extend defaults reported by spring-boot.

Metrics are also exported to the path /prometheus if the zipkin-autoconfigure-metrics-prometheus is available in the classpath. See the prometheus metrics README for more information.

Collector

Collector metrics are broken down by transport. The following are exported to the "/metrics" endpoint:

Metric	Description
counter.zipkin_collector.messages.$transport	cumulative messages received; should relate to messages reported by instrumented apps
counter.zipkin_collector.messages_dropped.$transport	cumulative messages dropped; reasons include client disconnects or malformed content
counter.zipkin_collector.bytes.$transport	cumulative message bytes
counter.zipkin_collector.spans.$transport	cumulative spans read; should relate to messages reported by instrumented apps
counter.zipkin_collector.spans_dropped.$transport	cumulative spans dropped; reasons include sampling or storage failures
gauge.zipkin_collector.message_spans.$transport	last count of spans in a message
gauge.zipkin_collector.message_bytes.$transport	last count of bytes in a message

Self-Tracing

Self tracing exists to help troubleshoot performance of the zipkin-server. Production deployments who enable self-tracing should lower the sample rate from 1.0 (100%) to a much smaller rate, like 0.001 (0.1% or 1 out of 1000).

When Brave dependencies are in the classpath, and zipkin.self-tracing.enabled=true, Zipkin will self-trace calls to the api.

yaml configuration binds the following environment variables to spring properties:

Variable	Property	Description
SELF_TRACING_ENABLED	zipkin.self-tracing.enabled	Set to true to enable self-tracing. Defaults to false
SELF_TRACING_SAMPLE_RATE`: Percentage of self-traces to retain, defaults to always sample (1.0).
SELF_TRACING_FLUSH_INTERVAL	zipkin.self-tracing.flush-interval	Interval in seconds to flush self-tracing data to storage. Defaults to 1

Configuration for the UI

Zipkin has a web UI, which is enabled by default when you depend on io.zipkin:zipkin-ui. This UI is automatically included in the exec jar, and is hosted by default on port 9411.

When the UI loads, it reads default configuration from the /config.json endpoint. These values can be overridden by system properties or any other alternative supported by Spring Boot.

Attribute	Property	Description
environment	zipkin.ui.environment	The value here becomes a label in the top-right corner. Not required.
defaultLookback	zipkin.ui.default-lookback	Default duration in millis to look back when finding traces. Affects the "Start time" element in the UI. Defaults to 3600000 (1 hour in millis).
searchEnabled	zipkin.ui.search-enabled	If the Find Traces screen is enabled. Defaults to true.
queryLimit	zipkin.ui.query-limit	Default limit for Find Traces. Defaults to 10.
instrumented	zipkin.ui.instrumented	Which sites this Zipkin UI covers. Regex syntax. e.g. http:\/\/example.com\/.* Defaults to match all websites (.*).
logsUrl	zipkin.ui.logs-url	Logs query service url pattern. If specified, a button will appear on the trace page and will replace {traceId} in the url by the traceId. Not required.
dependency.lowErrorRate	zipkin.ui.dependency.low-error-rate	The rate of error calls on a dependency link that turns it yellow. Defaults to 0.5 (50%) set to >1 to disable.
dependency.highErrorRate	zipkin.ui.dependency.high-error-rate	The rate of error calls on a dependency link that turns it red. Defaults to 0.75 (75%) set to >1 to disable.
basePath	zipkin.ui.basepath	path prefix placed into the tag in the UI HTML; useful when running behind a reverse proxy. Default "/zipkin"

For example, if using docker you can set ZIPKIN_UI_QUERY_LIMIT=100 to affect $.queryLimit in /config.json.

Environment Variables

zipkin-server is a drop-in replacement for the scala query service.

yaml configuration binds the following environment variables from zipkin-scala:

• QUERY_PORT: Listen port for the http api and web ui; Defaults to 9411
• QUERY_ENABLED: false disables the query api and UI assets. Search may also be disabled for the storage backend if it is not needed; Defaults to true
• SEARCH_ENABLED: false disables trace search requests on the storage backend. Does not disable trace by ID or dependency queries. Disable this when you use another service (such as logs) to find trace IDs; Defaults to true
• QUERY_LOG_LEVEL: Log level written to the console; Defaults to INFO
• QUERY_LOOKBACK: How many milliseconds queries can look back from endTs; Defaults to 24 hours (two daily buckets: one for today and one for yesterday)
• STORAGE_TYPE: SpanStore implementation: one of mem, mysql, cassandra, elasticsearch
• COLLECTOR_SAMPLE_RATE: Percentage of traces to retain, defaults to always sample (1.0).
• AUTOCOMPLETE_KEYS: list of span tag keys which will be returned by the /api/v2/autocompleteTags endpoint

Cassandra Storage

Zipkin's Cassandra storage component supports version 3.11+ and applies when STORAGE_TYPE is set to cassandra3:

* `CASSANDRA_KEYSPACE`: The keyspace to use. Defaults to "zipkin2"
* `CASSANDRA_CONTACT_POINTS`: Comma separated list of host addresses part of Cassandra cluster. You can also specify a custom port with 'host:port'. Defaults to localhost on port 9042.
* `CASSANDRA_LOCAL_DC`: Name of the datacenter that will be considered "local" for latency load balancing. When unset, load-balancing is round-robin.
* `CASSANDRA_ENSURE_SCHEMA`: Ensuring cassandra has the latest schema. If enabled tries to execute scripts in the classpath prefixed with `cassandra-schema-cql3`. Defaults to true
* `CASSANDRA_USERNAME` and `CASSANDRA_PASSWORD`: Cassandra authentication. Will throw an exception on startup if authentication fails. No default
* `CASSANDRA_USE_SSL`: Requires `javax.net.ssl.trustStore` and `javax.net.ssl.trustStorePassword`, defaults to false.

The following are tuning parameters which may not concern all users:

* `CASSANDRA_MAX_CONNECTIONS`: Max pooled connections per datacenter-local host. Defaults to 8
* `CASSANDRA_INDEX_CACHE_MAX`: Maximum trace index metadata entries to cache. Zero disables caching. Defaults to 100000.
* `CASSANDRA_INDEX_CACHE_TTL`: How many seconds to cache index metadata about a trace. Defaults to 60.
* `CASSANDRA_INDEX_FETCH_MULTIPLIER`: How many more index rows to fetch than the user-supplied query limit. Defaults to 3.

Example usage with logging:

$ STORAGE_TYPE=cassandra3 java -jar zipkin.jar --logging.level.zipkin=trace --logging.level.zipkin2=trace --logging.level.com.datastax.driver.core=debug

Elasticsearch Storage

Zipkin's Elasticsearch storage component supports versions 2-6.x and applies when STORAGE_TYPE is set to elasticsearch

The following apply when STORAGE_TYPE is set to elasticsearch:

* `ES_HOSTS`: A comma separated list of elasticsearch base urls to connect to ex. http://host:9200.
              Defaults to "http://localhost:9200".
* `ES_PIPELINE`: Only valid when the destination is Elasticsearch 5+. Indicates the ingest
                 pipeline used before spans are indexed. No default.
* `ES_TIMEOUT`: Controls the connect, read and write socket timeouts (in milliseconds) for
                Elasticsearch Api. Defaults to 10000 (10 seconds)
* `ES_MAX_REQUESTS`: Only valid when the transport is http. Sets maximum in-flight requests from
                     this process to any Elasticsearch host. Defaults to 64.
* `ES_INDEX`: The index prefix to use when generating daily index names. Defaults to zipkin.
* `ES_DATE_SEPARATOR`: The date separator to use when generating daily index names. Defaults to '-'.
* `ES_INDEX_SHARDS`: The number of shards to split the index into. Each shard and its replicas
                     are assigned to a machine in the cluster. Increasing the number of shards
                     and machines in the cluster will improve read and write performance. Number
                     of shards cannot be changed for existing indices, but new daily indices
                     will pick up changes to the setting. Defaults to 5.
* `ES_INDEX_REPLICAS`: The number of replica copies of each shard in the index. Each shard and
                       its replicas are assigned to a machine in the cluster. Increasing the
                       number of replicas and machines in the cluster will improve read
                       performance, but not write performance. Number of replicas can be changed
                       for existing indices. Defaults to 1. It is highly discouraged to set this
                       to 0 as it would mean a machine failure results in data loss.
* `ES_USERNAME` and `ES_PASSWORD`: Elasticsearch basic authentication, which defaults to empty string.
                                   Use when X-Pack security (formerly Shield) is in place.
* `ES_HTTP_LOGGING`: When set, controls the volume of HTTP logging of the Elasticsearch Api.
                     Options are BASIC, HEADERS, BODY

Example usage:

To connect normally:

$ STORAGE_TYPE=elasticsearch ES_HOSTS=http://myhost:9200 java -jar zipkin.jar

To log Elasticsearch api requests:

$ STORAGE_TYPE=elasticsearch ES_HTTP_LOGGING=BASIC java -jar zipkin.jar

Legacy (v1) storage components

The following components are no longer encouraged, but exist to help aid transition to supported ones. These are indicated as "v1" as they use data layouts based on Zipkin's V1 Thrift model, as opposed to the simpler v2 data model currently used.

MySQL Storage

The following apply when STORAGE_TYPE is set to mysql:

* `MYSQL_DB`: The database to use. Defaults to "zipkin".
* `MYSQL_USER` and `MYSQL_PASS`: MySQL authentication, which defaults to empty string.
* `MYSQL_HOST`: Defaults to localhost
* `MYSQL_TCP_PORT`: Defaults to 3306
* `MYSQL_MAX_CONNECTIONS`: Maximum concurrent connections, defaults to 10
* `MYSQL_USE_SSL`: Requires `javax.net.ssl.trustStore` and `javax.net.ssl.trustStorePassword`, defaults to false.

Alternatively you can use MYSQL_JDBC_URL and specify the complete JDBC url yourself. Note that the URL constructed by using the separate settings above will also include the following parameters: ?autoReconnect=true&useSSL=false&useUnicode=yes&characterEncoding=UTF-8. If you specify the JDBC url yourself, add these parameters as well.

Example usage:

$ STORAGE_TYPE=mysql MYSQL_USER=root java -jar zipkin.jar

Cassandra Storage

Zipkin's Legacy (v1) Cassandra storage component supports version 2.2+ and applies when STORAGE_TYPE is set to cassandra:

The environment variables are the same as STORAGE_TYPE=cassandra3, except the default keyspace name is "zipkin".

Example usage:

$ STORAGE_TYPE=cassandra java -jar zipkin.jar

Service and Span names query

The Zipkin Api does not include a parameter for how far back to look for service or span names. In order to prevent excessive load, service and span name queries are limited by QUERY_LOOKBACK, which defaults to 24hrs (two daily buckets: one for today and one for yesterday)

HTTP Collector

The HTTP collector is enabled by default. It accepts spans via POST /api/v1/spans and POST /api/v2/spans. The HTTP collector supports the following configuration:

Property	Environment Variable	Description
zipkin.collector.http.enabled	HTTP_COLLECTOR_ENABLED	false disables the HTTP collector. Defaults to true.

Scribe (Legacy) Collector

A collector supporting Scribe is available as an external module. See zipkin-autoconfigure/collector-scribe.

Kafka Collector

The Kafka collector is enabled when KAFKA_BOOTSTRAP_SERVERS is set to a v0.10+ server. The following apply and are further documented here.

Variable	New Consumer Config	Description
KAFKA_BOOTSTRAP_SERVERS	bootstrap.servers	Comma-separated list of brokers, ex. 127.0.0.1:9092. No default
KAFKA_GROUP_ID	group.id	The consumer group this process is consuming on behalf of. Defaults to zipkin
KAFKA_TOPIC	N/A	Comma-separated list of topics that zipkin spans will be consumed from. Defaults to zipkin
KAFKA_STREAMS	N/A	Count of threads consuming the topic. Defaults to 1

Example usage:

$ KAFKA_BOOTSTRAP_SERVERS=127.0.0.1:9092 java -jar zipkin.jar

Example targeting Kafka running in Docker:

$ export KAFKA_BOOTSTRAP_SERVERS=$(docker-machine ip `docker-machine active`)
# Run Kafka in the background
$ docker run -d -p 9092:9092 \
    --env ADVERTISED_HOST=$KAFKA_BOOTSTRAP_SERVERS \
    --env AUTO_CREATE_TOPICS=true \
    spotify/kafka
# Start the zipkin server, which reads $KAFKA_BOOTSTRAP_SERVERS
$ java -jar zipkin.jar

Overriding other properties

You may need to override other consumer properties than what zipkin explicitly defines. In such case, you need to prefix that property name with "zipkin.collector.kafka.overrides" and pass it as a CLI argument or system property.

For example, to override "overrides.auto.offset.reset", you can set a prefixed system property:

$ KAFKA_BOOTSTRAP_SERVERS=127.0.0.1:9092 java -Dzipkin.collector.kafka.overrides.auto.offset.reset=largest -jar zipkin.jar

Kafka (Legacy) Collector

The default collector is for Kafka 0.10.x+ brokers. You can use Kafka 0.8 brokers via an external module. See zipkin-autoconfigure/collector-kafka08.

RabbitMQ collector

The RabbitMQ collector will be enabled when the addresses or uri for the RabbitMQ server(s) is set.

Example usage:

$ RABBIT_ADDRESSES=localhost java -jar zipkin.jar

128-bit trace IDs

Zipkin supports 64 and 128-bit trace identifiers, typically serialized as 16 or 32 character hex strings. By default, spans reported to zipkin with the same trace ID will be considered in the same trace.

For example, 463ac35c9f6413ad48485a3953bb6124 is a 128-bit trace ID, while 48485a3953bb6124 is a 64-bit one.

Note: Span (or parent) IDs within a trace are 64-bit regardless of the length or value of their trace ID.

Migrating from 64 to 128-bit trace IDs

Unless you only issue 128-bit traces when all applications support them, the process of updating applications from 64 to 128-bit trace IDs results in a mixed state. This mixed state is mitigated by the setting STRICT_TRACE_ID=false, explained below. Once a migration is complete, remove the setting STRICT_TRACE_ID=false or set it to true.

Here are a few trace IDs the help what happens during this setting.

• Trace ID A: 463ac35c9f6413ad48485a3953bb6124
• Trace ID B: 48485a3953bb6124
• Trace ID C: 463ac35c9f6413adf1a48a8cff464e0e
• Trace ID D: 463ac35c9f6413ad

In a 64-bit environment, trace IDs will look like B or D above. When an application upgrades to 128-bit instrumentation and decides to create a 128-bit trace, its trace IDs will look like A or C above.

Applications who aren't yet 128-bit capable typically only retain the right-most 16 characters of the trace ID. When this happens, the same trace could be reported as trace ID A or trace ID B.

By default, Zipkin will think these are different trace IDs, as they are different strings. During a transition from 64-128 bit trace IDs, spans would appear split across two IDs. For example, it might start as trace ID A, but the next hop might truncate it to trace ID B. This would render the system unusable for applications performing upgrades.

One way to address this problem is to not use 128-bit trace IDs until all applications support them. This prevents a mixed scenario at the cost of coordination. Another way is to set STRICT_TRACE_ID=false.

When STRICT_TRACE_ID=false, only the right-most 16 of a 32 character trace ID are considered when grouping or retrieving traces. This setting should only be applied when transitioning from 64 to 128-bit trace IDs and removed once the transition is complete.

See openzipkin/b3-propagation#6 for the status of known open source libraries on 128-bit trace identifiers.

See zipkin2.storage.StorageComponent.Builder for even more details!

Running with Docker

Released versions of zipkin-server are published to Docker Hub as openzipkin/zipkin. See docker-zipkin for details.

Building locally

To build and run the server from the currently checked out source, enter the following.

# Build the server and also make its dependencies
$ ./mvnw -Dlicense.skip=true -DskipTests --also-make -pl zipkin-server clean install
# Run the server
$ java -jar ./zipkin-server/target/zipkin-server-*exec.jar