Apache NiFi already in use for an active callback or an InputStream created by ProcessSession.read(FlowFile) has not been closed

[#1]

I am getting following error in NiFi `ExecuteScript` processor.

```java

18:07:09 UTCERROR9e1d9c5e-0188-1000-ffff-fffffbc25817

10.42.62.250:8080ExecuteScript[id=9e1d9c5e-0188-1000-ffff-fffffbc25817] ExecuteScript[id=9e1d9c5e-0188-1000-ffff-fffffbc25817] failed to process due to org.apache.nifi.processor.exception.ProcessException: javax.script.ScriptException: java.lang.IllegalStateException: java.lang.IllegalStateException: StandardFlowFileRecord[uuid=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,claim=StandardContentClaim [resourceClaim=StandardResourceClaim[id=1686706804350-73290, container=default, section=586], offset=6556, length=39642],offset=0,name=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,size=39642] already in use for an active callback or an InputStream created by ProcessSession.read(FlowFile) has not been closed in <script> at line number 37

- Caused by: javax.script.ScriptException: java.lang.IllegalStateException: java.lang.IllegalStateException: StandardFlowFileRecord[uuid=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,claim=StandardContentClaim [resourceClaim=StandardResourceClaim[id=1686706804350-73290, container=default, section=586], offset=6556, length=39642],offset=0,name=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,size=39642] already in use for an active callback or an InputStream created by ProcessSession.read(FlowFile) has not been closed in <script> at line number 37

- Caused by: Traceback (most recent call last):

  File "<script>", line 37, in <module>

at org.apache.nifi.controller.repository.StandardProcessSession.validateRecordState(StandardProcessSession.java:3715)

at org.apache.nifi.controller.repository.StandardProcessSession.validateRecordState(StandardProcessSession.java:3710)

at org.apache.nifi.controller.repository.StandardProcessSession.transfer(StandardProcessSession.java:2349)

at jdk.internal.reflect.GeneratedMethodAccessor2736.invoke(Unknown Source)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.base/java.lang.reflect.Method.invoke(Unknown Source)

java.lang.IllegalStateException: java.lang.IllegalStateException: StandardFlowFileRecord[uuid=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,claim=StandardContentClaim [resourceClaim=StandardResourceClaim[id=1686706804350-73290, container=default, section=586], offset=6556, length=39642],offset=0,name=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,size=39642] already in use for an active callback or an InputStream created by ProcessSession.read(FlowFile) has not been closed

- Caused by: java.lang.IllegalStateException: StandardFlowFileRecord[uuid=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,claim=StandardContentClaim [resourceClaim=StandardResourceClaim[id=1686706804350-73290, container=default, section=586], offset=6556, length=39642],offset=0,name=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,size=39642] already in use for an active callback or an InputStream created by ProcessSession.read(FlowFile) has not been closed; rolling back session: {}

18:07:09 UTCERROR9e1d9c5e-0188-1000-ffff-fffffbc25817

10.42.62.250:8080ExecuteScript[id=9e1d9c5e-0188-1000-ffff-fffffbc25817] Processing failed: org.apache.nifi.processor.exception.ProcessException: javax.script.ScriptException: java.lang.IllegalStateException: java.lang.IllegalStateException: StandardFlowFileRecord[uuid=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,claim=StandardContentClaim [resourceClaim=StandardResourceClaim[id=1686706804350-73290, container=default, section=586], offset=6556, length=39642],offset=0,name=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,size=39642] already in use for an active callback or an InputStream created by ProcessSession.read(FlowFile) has not been closed in <script> at line number 37

- Caused by: javax.script.ScriptException: java.lang.IllegalStateException: java.lang.IllegalStateException: StandardFlowFileRecord[uuid=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,claim=StandardContentClaim [resourceClaim=StandardResourceClaim[id=1686706804350-73290, container=default, section=586], offset=6556, length=39642],offset=0,name=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,size=39642] already in use for an active callback or an InputStream created by ProcessSession.read(FlowFile) has not been closed in <script> at line number 37

- Caused by: Traceback (most recent call last):

  File "<script>", line 37, in <module>

at org.apache.nifi.controller.repository.StandardProcessSession.validateRecordState(StandardProcessSession.java:3715)

at org.apache.nifi.controller.repository.StandardProcessSession.validateRecordState(StandardProcessSession.java:3710)

at org.apache.nifi.controller.repository.StandardProcessSession.transfer(StandardProcessSession.java:2349)

at jdk.internal.reflect.GeneratedMethodAccessor2736.invoke(Unknown Source)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.base/java.lang.reflect.Method.invoke(Unknown Source)

java.lang.IllegalStateException: java.lang.IllegalStateException: StandardFlowFileRecord[uuid=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,claim=StandardContentClaim [resourceClaim=StandardResourceClaim[id=1686706804350-73290, container=default, section=586], offset=6556, length=39642],offset=0,name=40d42213-2c7a-49a2-8c5d-5a7fc58bad2d,size=39642] already in use for an active callback or an InputStream created by ProcessSession.read(FlowFile) has not been closed

```

I am trying to run following script in NiFi `ExecuteScript` processor

```

import xml.etree.ElementTree as ET

import os

import java.io

from org.apache.commons.io import IOUtils

from java.nio.charset import StandardCharsets

def find_pattern_in_xml(file_path, target_string):

    tree = ET.ElementTree(ET.fromstring(file_path))

    root = tree.getroot()

    found_elements = []

    # Iterate through all elements in the XML tree

    for element in root.iter():

        # Check if the target string is present in the element text

        if target_string in element.text:

            found_elements.append(element)

    return found_elements

flowFile = session.get()

if flowFile is not None:

    try:

        stream_content = session.read(flowFile)

        text_content = IOUtils.toString(stream_content, StandardCharsets.UTF_8)

        # flowfile_path = flowFile.getAttribute('sourceFileName')

        target_string = "~Indv"

        found_elements = find_pattern_in_xml(flowfile_path, target_string)

        # Print the found elements

        for element in found_elements:

            session.remove(flowFile)

            print(element.tag, element.text)

    except Exception as e:

        # Log the error and route the flowfile to failure

        log.error("Error processing flowfile"+ str(e))

        session.transfer(flowFile, REL_FAILURE)

session.commit()

```

[#2]

@pdesh Welcome to the Cloudera Community!

To help you get the best possible solution, I have tagged our NiFi experts @MattWho and @cotopaul  who may be able to assist you further.

Please keep us updated on your post, and we hope you find a satisfactory solution to your query.

[#3]

This is likely what's generating the error... You're saying remove the Flow file in a loop and should only be done once.

for element in found_elements:

            session.remove(flowFile)

            print(element.tag, element.text)