wso2 : How to read message from Message Store using Message Processor?

I'm trying to read the messages i've stored in my Message store using a processor, by printing it through logs, but i'm unable to.

My Message Processor code (i've included the log and file I want to write to in the testSeq)

<?xml version="1.0" encoding="UTF-8"?>
<messageProcessor class="org.apache.synapse.message.processor.impl.sampler.SamplingProcessor" messageStore="JDBC_MESSAGE_STORE" name="JDBC_MESSAGE_PROCESSOR" xmlns="http://ws.apache.org/ns/synapse">
    <parameter name="sequence">testSeq</parameter>
    <parameter name="interval">20000</parameter>
    <parameter name="is.active">true</parameter>
</messageProcessor>

My proxy that I use to insert values into jdbc message store: (works successfully)

<inSequence>
            <iterate continueParent="true" expression="//ns:dbResponse/ns:data" id="Iterate-over-xml" sequential="true" xmlns:ns="http://dss.testdb">
                <target>
                    <sequence>
                        <store messageStore="JDBC_MESSAGE_STORE"/>
                    </sequence>
                </target>
            </iterate>
 <respond/>
</inSequence>

Could anyone tell me what i'm doing wrong?

No worries! I figured it out, basically since there was an error with the ep sequence that I had specified originally, the processor got deactivated then and remained that way. The solution that worked for me was to delete the message processor xml, restart the ESB and then add the message processor again.