Package org.apache.accumulo.core.trace

Class TraceUtil

java.lang.Object

org.apache.accumulo.core.trace.TraceUtil

public class TraceUtil
extends Object

Utility class for tracing within Accumulo. Not intended for client use!

Field Summary

Fields

Modifier and Type	Field	Description
static String	TRACE_HOST_PROPERTY
static String	TRACE_SERVICE_PROPERTY
static String	TRACER_ZK_HOST
static String	TRACER_ZK_PATH
static String	TRACER_ZK_TIMEOUT

Constructor Summary

Constructors

Constructor	Description
TraceUtil()

Method Summary

Modifier and Type	Method	Description
static org.apache.htrace.impl.CountSampler	countSampler(long frequency)
static void	disable()	Disable tracing by closing SpanReceivers for the current process.
static void	enableClientTraces(String hostname, String service, Properties properties)	Enable tracing by setting up SpanReceivers for the current process.
static void	enableServerTraces(String hostname, String service, AccumuloConfiguration conf)	Enable tracing by setting up SpanReceivers for the current process.
static org.apache.htrace.impl.ProbabilitySampler	probabilitySampler(double fraction)
static org.apache.htrace.TraceScope	trace(TInfo info, String description)	Continue a trace by starting a new span with a given parent and description.
static TInfo	traceInfo()	Obtain TInfo for the current span.
static <T> T	wrapClient(T instance)	To move trace data from client to server, the RPC call must be annotated to take a TInfo object as its first argument.
static <T> T	wrapService(T instance)

Methods inherited from class java.lang.Object

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

Field Detail

TRACE_HOST_PROPERTY

public static final String TRACE_HOST_PROPERTY

See Also:

Constant Field Values

TRACE_SERVICE_PROPERTY

public static final String TRACE_SERVICE_PROPERTY

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Constant Field Values

TRACER_ZK_HOST

public static final String TRACER_ZK_HOST

See Also:

Constant Field Values

TRACER_ZK_TIMEOUT

public static final String TRACER_ZK_TIMEOUT

See Also:

Constant Field Values

TRACER_ZK_PATH

public static final String TRACER_ZK_PATH

See Also:

Constant Field Values

Constructor Detail

TraceUtil

public TraceUtil()

Method Detail

enableClientTraces

public static void enableClientTraces(String hostname,
                                      String service,
                                      Properties properties)

Enable tracing by setting up SpanReceivers for the current process. If host name is null, it will be determined. If service name is null, the simple name of the class will be used. Properties required in the client configuration include ClientProperty.TRACE_SPAN_RECEIVERS and any properties specific to the span receiver.

enableServerTraces

public static void enableServerTraces(String hostname,
                                      String service,
                                      AccumuloConfiguration conf)

Enable tracing by setting up SpanReceivers for the current process. If host name is null, it will be determined. If service name is null, the simple name of the class will be used.

disable

public static void disable()

Disable tracing by closing SpanReceivers for the current process.

trace

public static org.apache.htrace.TraceScope trace(TInfo info,
                                                 String description)

Continue a trace by starting a new span with a given parent and description.

traceInfo

public static TInfo traceInfo()

Obtain TInfo for the current span.

countSampler

public static org.apache.htrace.impl.CountSampler countSampler(long frequency)

probabilitySampler

public static org.apache.htrace.impl.ProbabilitySampler probabilitySampler(double fraction)

wrapClient

public static <T> T wrapClient(T instance)

To move trace data from client to server, the RPC call must be annotated to take a TInfo object as its first argument. The user can simply pass null, so long as they wrap their Client and Service objects with these functions.

 Trace.on("remoteMethod");
 Iface c = new Client();
 c = TraceWrap.client(c);
 c.remoteMethod(null, arg2, arg3);
 Trace.off();
 

The wrapper will see the annotated method and send or re-establish the trace information. Note that the result of these calls is a Proxy object that conforms to the basic interfaces, but is not your concrete instance.

wrapService

public static <T> T wrapService(T instance)