bands input in load_collection causes error

[lforesta]

In a process graph, when adding the bands input, e.g.

"dc": {
    "process_id": "load_collection",
    "arguments": {
      "id": "CGS_SENTINEL2_RADIOMETRY_V102_001",
      "spatial_extent": {
        "west": 2.052030657924054,
        "east": 4.063236553549667,
        "north": 51.00726308446294,
        "south": 50.99458367677388,
        "crs": "EPSG:4326"
        },
      "temporal_extent": [
        "2018-06-04T00:00:00.000Z",
        "2018-06-23T00:00:00.000Z"
      ],
      "bands": ["8", "4"]
    },
    "result": false
  }

the back-end returns the following error:

{"message":"An error occurred while calling z:org.openeo.geotrellis.geotiff.package.saveStitched.\n: org.apache.spark.SparkException: Job aborted due to stage failure: Task 23 in stage 266.0 failed 4 times, most recent failure: Lost task 23.3 in stage 266.0 (TID 35790, epod53.vgt.vito.be, executor 147): java.lang.ClassCastException\n\nDriver stacktrace:\n\tat org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1651)\n\tat org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1639)\n\tat org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1638)\n\tat scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)\n\tat scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)\n\tat org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1638)\n\tat org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:831)\n\tat org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:831)\n\tat scala.Option.foreach(Option.scala:257)\n\tat org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:831)\n\tat org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:1872)\n\tat org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1821)\n\tat org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1810)\n\tat org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48)\n\tat org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:642)\n\tat org.apache.spark.SparkContext.runJob(SparkContext.scala:2034)\n\tat org.apache.spark.SparkContext.runJob(SparkContext.scala:2055)\n\tat org.apache.spark.SparkContext.runJob(SparkContext.scala:2074)\n\tat org.apache.spark.SparkContext.runJob(SparkContext.scala:2099)\n\tat org.apache.spark.rdd.RDD$$anonfun$collect$1.apply(RDD.scala:945)\n\tat org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:151)\n\tat org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:112)\n\tat org.apache.spark.rdd.RDD.withScope(RDD.scala:363)\n\tat org.apache.spark.rdd.RDD.collect(RDD.scala:944)\n\tat geotrellis.spark.stitch.SpatialTileLayoutRDDStitchMethods.stitch(StitchRDDMethods.scala:81)\n\tat org.openeo.geotrellis.geotiff.package$.saveStitched(package.scala:39)\n\tat org.openeo.geotrellis.geotiff.package$.saveStitched(package.scala:28)\n\tat org.openeo.geotrellis.geotiff.package.saveStitched(package.scala)\n\tat sun.reflect.GeneratedMethodAccessor73.invoke(Unknown Source)\n\tat sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\n\tat java.lang.reflect.Method.invoke(Method.java:498)\n\tat py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)\n\tat py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)\n\tat py4j.Gateway.invoke(Gateway.java:282)\n\tat py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)\n\tat py4j.commands.CallCommand.execute(CallCommand.java:79)\n\tat py4j.GatewayConnection.run(GatewayConnection.java:238)\n\tat java.lang.Thread.run(Thread.java:748)\nCaused by: java.lang.ClassCastException\n"}

If the bands input is not given, everything works fine. If needed I can provide full examples for this.

[soxofaan]

which backend url are you using?
a full code example that triggers the issue would also help indeed

[lforesta]

I am using this url: http://openeo.vgt.vito.be/openeo/0.4.0

The following process graph works (no bands specified anywhere):

{
  "dc": {
    "process_id": "load_collection",
    "arguments": {
      "id": "CGS_SENTINEL2_RADIOMETRY_V102_001",
      "spatial_extent": {
        "west": 2.052030657924054,
        "east": 4.063236553549667,
        "north": 51.00726308446294,
        "south": 50.99458367677388,
        "crs": "EPSG:4326"
        },
      "temporal_extent": [
        "2018-06-04T00:00:00.000Z",
        "2018-06-23T00:00:00.000Z"
      ]
    },
    "result": false
  },
  "ndvi": {
    "process_id": "ndvi",
    "arguments": {
      "data": {"from_node": "dc"}
    }
  },
  "min_time": {
    "process_id": "reduce",
    "arguments": {
      "data": {
        "from_node": "ndvi"
      },
      "reducer": {
        "callback": {
          "min": {
            "arguments": {
              "data": {
                "from_argument": "data"
              }
            },
            "process_id": "min",
            "result": true
          }
        }
      },
      "dimension": "temporal"
    }
  },
  "save_output": {
    "process_id": "save_result",
    "arguments": {
      "data": {
        "from_node": "min_time"
      },
      "format": "Gtiff"
    },
    "result": true
  }
}

Adding the input bands with band names "nir" and "red" in the first node "dc" causes the error above

"dc": {
    "process_id": "load_collection",
    "arguments": {
      "id": "CGS_SENTINEL2_RADIOMETRY_V102_001",
      "spatial_extent": {
        "west": 2.052030657924054,
        "east": 4.063236553549667,
        "north": 51.00726308446294,
        "south": 50.99458367677388,
        "crs": "EPSG:4326"
        },
      "temporal_extent": [
        "2018-06-04T00:00:00.000Z",
        "2018-06-23T00:00:00.000Z"
      ],
      "bands": ["nir", "red"]
    },
    "result": false
  }

If the bands are specified by their band_id ["8", "4"] (collection metadata), there is an integer/string error:
{"message":"java.lang.String cannot be cast to java.lang.Integer"}

If the bands are specified as integers [8, 4], they don't exist:
{"message":"Band 8 does not exist"}

[soxofaan]

thanks for the info
is probably also related to Open-EO/openeo-python-client#76

[soxofaan]

should be fixed with commits above
(still to be deployed at the moment)