# APM Tracing Bridge - Span.log.error() Problem

**URL:** <https://discuss.elastic.co/t/apm-tracing-bridge-span-log-error-problem/237404>\
**Category:** APM\
**Tags:** java\
**Created:** [June 17, 2020, 6:27am UTC](https://discuss.elastic.co/t/apm-tracing-bridge-span-log-error-problem/237404 "2020-06-17T06:27:40Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![KeithW](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/keithw/32/70498_2.png) [@KeithW](https://discuss.elastic.co/u/KeithW)\
**Post date:** [June 17, 2020, 6:27am UTC](https://discuss.elastic.co/t/apm-tracing-bridge-span-log-error-problem/237404/1 "2020-06-17T06:27:40Z")

</div>

HI

I have some custom spans that trace given business operations. These spans may have child spans with the same process.

According to [https://www.elastic.co/guide/en/apm/agent/java/current/opentracing-bridge.html#logs](https://www.elastic.co/guide/en/apm/agent/java/current/opentracing-bridge.html#logs), I should be able to log an error for a span like this:

```auto
    Exception e = ...
    span.log(
        Map.of(
            "event", "error",
            "error.object", e
        )
    )

```

Unfortunately I can't get this working for any type of span (parent or child). I can see spans in the APM dashboard (if they are `.finished()`), however if I log errors against them I don't see any errors.

I do see other errors for rest calls that get automatically added by the attach agent, so in general errors are working. In the API console `GET apm-7.6.2-error/_ilm/explain` returns ok. Errors just don't seem to be working for our custom spans.

Versions:  
APM Server version: `apm-server:7.6.2`  
APM Agent Version (Java): `co.elastic.apm:apm-agent-attach@1.16.0`  
APM Bridge Version (Java): `co.elastic.apm:apm-opentracing@1.16.0`

Couple of questions:

1. any ideas on the above?
2. if a span errors, should we also call finish()?

Appreciate any help

Regards

Keith

---

<div class="post-metadata">

**Author:** ![Eyal\_Koren](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/eyal_koren/32/36830_2.png) [@Eyal\_Koren](https://discuss.elastic.co/u/Eyal_Koren)\
**Post date:** [June 17, 2020, 8:01am UTC](https://discuss.elastic.co/t/apm-tracing-bridge-span-log-error-problem/237404/2 "2020-06-17T08:01:56Z")

</div>

Hi and welcome to our forum!

> [@KeithW](#):
>
> if a span errors, should we also call finish()?

Yes, a span is reported only if it is `finish`ed. An error is sent as a separate event.

> [@KeithW](#):
>
> any ideas on the above?

Try to debug and see if the span you are calling the `log` on is a valid one and not a `noop`. Also, set the agent's `log_level` to `DEBUG` and see if you find anything interesting. If you set it to `TRACE`, the agent will also log all events it sends to the APM server.  
I hope this helps you figuring this out.

---

<div class="post-metadata">

**Author:** ![KeithW](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/keithw/32/70498_2.png) [@KeithW](https://discuss.elastic.co/u/KeithW)\
**Post date:** [June 17, 2020, 11:07am UTC](https://discuss.elastic.co/t/apm-tracing-bridge-span-log-error-problem/237404/3 "2020-06-17T11:07:43Z")

</div>

Thanks for reply the welcome 🙂

The span is of type `co.elastic.apm.opentracing.ApmSpan`, so not a noop.

To narrow this down, I created a test span, started, logged an error, then finished it.

```auto
io.opentracing.Span span = this.elasticApmTracer
    .buildSpan("Test-Error-Span")
    .start();
span.log(
    ImmutableMap.of(
        "event", "BOOM-Exception",
        "error.object", new Exception("BOOM")
    )
);
span.finish();

```

I bumped the log level as you suggested (nice tip). I didn't notice any smoking guns. There were a few flush calls which contained the test trace:

```auto
DEBUG co.elastic.apm.agent.report.IntakeV2ReportingEventHandler - Receiving FLUSH event (sequence 53)
TRACE co.elastic.apm.agent.report.serialize.DslJsonSerializer ...

```

The json that got flushed had the trace, but no error details:

```auto
{
  "transaction": {
    "timestamp": 1592390077519004,
    "name": "Test-Error-Span",
    "id": "a1de5eeb641f807f",
    "trace_id": "4d9ac1981d005b6cf2a80d1724145c6c",
    "type": "unknown",
    "duration": 4.298,
    "context": {
      "tags": {}
    },
    "span_count": {
      "dropped": 0,
      "started": 0
    },
    "sampled": true
  }
}

... in a later flush  

{
  "metricset": {
    "timestamp": 1592390103155000,
    "transaction": {
      "name": "Test-Error-Span",
      "type": "unknown"
    },
    "span": {
      "type": "app",
      "subtype": null
    },
    "tags": {},
    "samples": {
      "span.self_time.count": {
        "value": 1
      },
      "span.self_time.sum.us": {
        "value": 4298
      }
    }
  }
}

  "metricset": {
    "timestamp": 1592390103155000,
    "transaction": {
      "name": "Test-Error-Span",
      "type": "unknown"
    },
    "tags": {},
    "samples": {
      "transaction.duration.count": {
        "value": 1
      },
      "transaction.duration.sum.us": {
        "value": 4298
      },
      "transaction.breakdown.count": {
        "value": 1
      }
    }
  }
}

```

I didn't see any text that was logged against the span (i.e. 'BOOM-Exception', or just 'BOOM');

The underlying `co.elastic.apm.opentracing.ApmSpan` seems to just have a noop for all logging calls:

```auto
    public ApmSpan log(String event) {
        this.log(Collections.singletonMap("event", event));
        return this;
    }

    public ApmSpan log(Map<String, ?> fields) {
        return this.log(-1L, fields);
    }

    public ApmSpan log(long timestampMicroseconds, String event) {
        this.log(timestampMicroseconds, Collections.singletonMap("event", event));
        return this;
    }

    public ApmSpan log(long timestampMicroseconds, Map<String, ?> fields) {
        return this;
    }

```

Not sure how that'd log anything unless there is some runtime weaving going on by the agent.  
(Edit: looks like the source does elude to some injection going on: [https://github.com/elastic/apm-agent-java/blob/master/apm-opentracing/src/main/java/co/elastic/apm/opentracing/ApmSpan.java](https://github.com/elastic/apm-agent-java/blob/master/apm-opentracing/src/main/java/co/elastic/apm/opentracing/ApmSpan.java))

Not sure what I'm doing wrong here?

Thanks for any help

---

<div class="post-metadata">

**Author:** ![Eyal\_Koren](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/eyal_koren/32/36830_2.png) [@Eyal\_Koren](https://discuss.elastic.co/u/Eyal_Koren)\
**Post date:** [June 17, 2020, 11:31am UTC](https://discuss.elastic.co/t/apm-tracing-bridge-span-log-error-problem/237404/4 "2020-06-17T11:31:04Z")

</div>

You need to use `error` as the value of the `event` key:

```auto
span.log(
    ImmutableMap.of(
        "event", "error",
        "error.object", new Exception("BOOM")
    )
);

```

This is what tells the agent to send an error event

---

<div class="post-metadata">

**Author:** ![KeithW](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/keithw/32/70498_2.png) [@KeithW](https://discuss.elastic.co/u/KeithW)\
**Post date:** [June 17, 2020, 11:31am UTC](https://discuss.elastic.co/t/apm-tracing-bridge-span-log-error-problem/237404/5 "2020-06-17T11:31:13Z")

</div>

I just figured this out, looking at [https://github.com/elastic/apm-agent-java/blob/master/apm-agent-plugins/apm-opentracing-plugin/src/main/java/co/elastic/apm/agent/opentracing/impl/ApmSpanInstrumentation.java#L137](https://github.com/elastic/apm-agent-java/blob/master/apm-agent-plugins/apm-opentracing-plugin/src/main/java/co/elastic/apm/agent/opentracing/impl/ApmSpanInstrumentation.java#L137), the value of `error` must be `error`. I seemed to have it as a message.

---

<div class="post-metadata">

**Author:** ![KeithW](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/keithw/32/70498_2.png) [@KeithW](https://discuss.elastic.co/u/KeithW)\
**Post date:** [June 17, 2020, 11:32am UTC](https://discuss.elastic.co/t/apm-tracing-bridge-span-log-error-problem/237404/6 "2020-06-17T11:32:02Z")

</div>

Thanks for the reply, i just figured it out. My bad. We'll was a fun investigation 🙂

Thanks for the help.

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [July 8, 2020, 7:32am UTC](https://discuss.elastic.co/t/apm-tracing-bridge-span-log-error-problem/237404/7 "2020-07-08T07:32:09Z")

</div>

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