zipkin2.storage

Class InMemoryStorage

java.lang.Object

zipkin2.Component

zipkin2.storage.StorageComponent

zipkin2.storage.InMemoryStorage

All Implemented Interfaces:

Closeable, AutoCloseable, SpanConsumer, SpanStore

public final class InMemoryStorage
extends StorageComponent
implements SpanStore, SpanConsumer

Test storage component that keeps all spans in memory, accepting them on the calling thread.

Internally, spans are indexed on 64-bit trace ID

Here's an example of some traces in memory:

 spansByTraceIdTimeStamp:
    <aaaa,July 4> --> ( spanA(time:July 4, traceId:aaaa, service:foo, name:GET),
                        spanB(time:July 4, traceId:aaaa, service:bar, name:GET) )
    <cccc,July 4> --> ( spanC(time:July 4, traceId:aaaa, service:foo, name:GET) )
    <bbbb,July 5> --> ( spanD(time:July 5, traceId:bbbb, service:biz, name:GET) )
    <bbbb,July 6> --> ( spanE(time:July 6, traceId:bbbb) service:foo, name:POST )

 traceIdToTraceIdTimeStamps:
    aaaa --> [ <aaaa,July 4> ]
    bbbb --> [ <bbbb,July 5>, <bbbb,July 6> ]
    cccc --> [ <cccc,July 4> ]

 serviceToTraceIds:
    foo --> [ <aaaa>, <cccc>, <bbbb> ]
    bar --> [ <aaaa> ]
    biz --> [ <bbbb> ]

 serviceToSpanNames:
    bar --> ( GET )
    biz --> ( GET )
    foo --> ( GET, POST )
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	InMemoryStorage.Builder

Method Summary

Modifier and Type	Method and Description
Call<Void>	accept(List<Span> spans)
int	acceptedSpanCount()
void	clear()
void	close() Closes any network resources created implicitly by the component.
List<DependencyLink>	getDependencies() Used for testing.
Call<List<DependencyLink>>	getDependencies(long endTs, long lookback) Returns dependency links derived from spans in an interval contained by (endTs - lookback) or empty if none are found.
Call<List<String>>	getServiceNames() Retrieves all local and remote service names, sorted lexicographically.
Call<List<String>>	getSpanNames(String service) Retrieves all span names recorded by a service, sorted lexicographically.
Call<List<Span>>	getTrace(String traceId) Retrieves spans that share a 128-bit trace id with no ordering expectation or empty if none are found.
List<List<Span>>	getTraces() Used for testing.
Call<List<List<Span>>>	getTraces(QueryRequest request) Retrieves spans grouped by trace ID from the storage system with no ordering expectation.
static InMemoryStorage.Builder	newBuilder()
SpanConsumer	spanConsumer()
InMemoryStorage	spanStore()

Methods inherited from class zipkin2.Component

check

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

newBuilder

public static InMemoryStorage.Builder newBuilder()

acceptedSpanCount

public int acceptedSpanCount()

clear

public void clear()

accept

public Call<Void> accept(List<Span> spans)

Specified by:

accept in interface SpanConsumer

getTraces

public Call<List<List<Span>>> getTraces(QueryRequest request)

Description copied from interface: SpanStore

Retrieves spans grouped by trace ID from the storage system with no ordering expectation.

When strict trace ID is disabled, spans are grouped by the right-most 16 characters of the trace ID.

Specified by:

getTraces in interface SpanStore

getTraces

public List<List<Span>> getTraces()

Used for testing. Returns all traces unconditionally.

getDependencies

public List<DependencyLink> getDependencies()

Used for testing. Returns all dependency links unconditionally.

getTrace

public Call<List<Span>> getTrace(String traceId)

Description copied from interface: SpanStore

Retrieves spans that share a 128-bit trace id with no ordering expectation or empty if none are found.

When strict trace ID is disabled, spans with the same right-most 16 characters are returned even if the characters to the left are not.

Implementations should use Span.normalizeTraceId(String) to ensure consistency.

Specified by:

getTrace in interface SpanStore

Parameters:

traceId - the trace ID

getServiceNames

public Call<List<String>> getServiceNames()

Description copied from interface: SpanStore

Retrieves all local and remote service names, sorted lexicographically.

Specified by:

getServiceNames in interface SpanStore

getSpanNames

public Call<List<String>> getSpanNames(String service)

Description copied from interface: SpanStore

Retrieves all span names recorded by a service, sorted lexicographically.

Specified by:

getSpanNames in interface SpanStore

getDependencies

public Call<List<DependencyLink>> getDependencies(long endTs,
                                                  long lookback)

Description copied from interface: SpanStore

Returns dependency links derived from spans in an interval contained by (endTs - lookback) or empty if none are found.

Implementations may bucket aggregated data, for example daily. When this is the case, endTs may be floored to align with that bucket, for example midnight if daily. lookback applies to the original endTs, even when bucketed. Using the daily example, if endTs was 11pm and lookback was 25 hours, the implementation would query against 2 buckets.

Some implementations parse spans from storage and call DependencyLinker to aggregate links. The reason is certain graph logic, such as skipping up the tree is difficult to implement as a storage query.

Spans are grouped by the right-most 16 characters of the trace ID. This ensures call counts are not incremented twice due to one hop downgrading from 128 to 64-bit trace IDs.

Specified by:

getDependencies in interface SpanStore

Parameters:

endTs - only return links from spans where Span.timestamp are at or before this time in epoch milliseconds.

lookback - only return links from spans where Span.timestamp are at or after (endTs - lookback) in milliseconds.

spanStore

public InMemoryStorage spanStore()

Specified by:

spanStore in class StorageComponent

spanConsumer

public SpanConsumer spanConsumer()

Specified by:

spanConsumer in class StorageComponent

close

public void close()

Description copied from class: Component

Closes any network resources created implicitly by the component.

For example, if this created a connection, it would close it. If it was provided one, this would close any sessions, but leave the connection open.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class Component