Query on PXF table failed with error "Unexpected character" when some special character in the xml file

Products

• VMware Tanzu Greenplum
• VMware Tanzu Greenplum / Gemfire

Issue/Introduction

When working with PXF, the query might fail with an error like:

ERROR: remote component error (500) from '127.0.0.1:5888'...
Unable to read configuration for server SQLServer from 
<PATH_TO_PXF_CONF>/servers/<Server_name> (libchurl.c:985) (seg0 slicel xxx.xxx.xxx.xxx:xxxx 
pid=74260) (libchurl.c:985)

The PXF log (located in $PXF_CONF/logs) on the segment host will give us more detail:

java.lang.RuntimeException: Unable to read configuration for server SQLServer from /usr/local/greenplum-db/pxf_conf/servers/SQLServer
...
Caused by: [com.ctc.wstx.exc.WstxLazyException] com.ctc.wstx.exc.WstxUnexpectedCharException: Unexpected character '2' (code 50) (expected a name start character)at [row,col,system-id]: [20,22,"file:/usr/local/greenplum-db/pxf_conf/servers/SQLServer/jdbc-site.xml] 
at [row,col,system-id]: [20,22,"file:/usr/local/greenplum-db/pxf_conf/servers/SQLServer/jdbc-site.xml] 
...

Resolution

Please check the XML file which reported with the error. To verify the syntax of the XML file, we can use "xmllint" utility:

# xmllint --format jdbc-site.xml

In this case, we found this line has an error:

$ xmllint --format jdbc-site.xml
jdbc-site.xml:20: parser error : xmlParseEntityRef: no name
        <value>matt&2020</value>

It is because the "&" mark can not be recognized by XML file, to fix this, we need to replace the "&" with the string "&"

        <value>matt&amp;2020</value>