Fetching from XML streams

xmlpipe2 source type lets you pass arbitrary full-text and attribute data to Manticore in yet another custom XML format. It also allows to specify the schema (ie. the set of fields and attributes) either in the XML stream itself, or in the source settings.

Declaration of XML stream

xmlpipe_command directive is mandatory and contains the shell command invoked to produce the XML stream which gets indexed. The command can just read a XML file but it can also be a program that generates on-the-fly the XML content.

XML file format

When indexing xmlpipe2 source, indexer runs the given command, opens a pipe to its stdout, and expects well-formed XML stream. Here’s sample stream data:

Example of XML document stream with schema built-in:

<?xml version="1.0" encoding="utf-8"?>
<sphinx:docset>

<sphinx:schema>
<sphinx:field name="subject"/>
<sphinx:field name="content"/>
<sphinx:attr name="published" type="timestamp"/>
<sphinx:attr name="author_id" type="int" bits="16" default="1"/>
</sphinx:schema>

<sphinx:document id="1234">
<content>this is the main content <![CDATA[[and this <cdata> entry
must be handled properly by xml parser lib]]></content>
<published>1012325463</published>
<subject>note how field/attr tags can be
in <b> class="red">randomized</b> order</subject>
<misc>some undeclared element</misc>
</sphinx:document>

<sphinx:document id="1235">
<subject>another subject</subject>
<content>here comes another document, and i am given to understand,
that in-document field order must not matter, sir</content>
<published>1012325467</published>
</sphinx:document>

<!-- ... even more sphinx:document entries here ... -->

<sphinx:killlist>
<id>1234</id>
<id>4567</id>
</sphinx:killlist>

</sphinx:docset>

Arbitrary fields and attributes are allowed. They also can occur in the stream in arbitrary order within each document; the order is ignored. There is a restriction on maximum field length; fields longer than 2 MB will be truncated to 2 MB (this limit can be changed in the source).

The schema, ie. complete fields and attributes list, must be declared before any document could be parsed. This can be done either in the configuration file using xmlpipe_field and xmlpipe_attr_XXX settings, or right in the stream using <sphinx:schema> element. <sphinx:schema> is optional. It is only allowed to occur as the very first sub-element in <sphinx:docset>. If there is no in-stream schema definition, settings from the configuration file will be used. Otherwise, stream settings take precedence. Note that the document id should be specified as a property id of tag <sphinx:document> (e.g. <sphinx:document id="1235">) and is supposed to be a unique signed positive non-zero 64-bit integer.

Unknown tags (which were not declared neither as fields nor as attributes) will be ignored with a warning. In the example above, <misc> will be ignored. All embedded tags and their attributes (such as ** in <subject> in the example above) will be silently ignored.

Support for incoming stream encodings depends on whether iconv is installed on the system. xmlpipe2 is parsed using libexpat parser that understands US-ASCII, ISO-8859-1, UTF-8 and a few UTF-16 variants natively. Manticore configure script will also check for libiconv presence, and utilize it to handle other encodings. libexpat also enforces the requirement to use UTF-8 charset on Manticore side, because the parsed data it returns is always in UTF-8.

XML elements (tags) recognized by xmlpipe2 (and their attributes where applicable) are:

• sphinx:docset - Mandatory top-level element, denotes and contains xmlpipe2 document set.
• sphinx:schema - Optional element, must either occur as the very first child of sphinx:docset, or never occur at all. Declares the document schema. Contains field and attribute declarations. If present, overrides per-source settings from the configuration file.
• sphinx:field - `Optional element, child of sphinx:schema. Declares a full-text field. Known attributes are:
  • “name”, specifies the XML element name that will be treated as a full-text field in the subsequent documents.
  • “attr”, specifies whether to also index this field as a string. Possible value is “string”.
• sphinx:attr - Optional element, child of sphinx:schema. Declares an attribute. Known attributes are:
  • “name”, specifies the element name that should be treated as an attribute in the subsequent documents.
  • “type”, specifies the attribute type. Possible values are “int”, “bigint”, “timestamp”, “bool”, “float”, “multi” and “json”.
  • “bits”, specifies the bit size for “int” attribute type. Valid values are 1 to 32.
  • “default”, specifies the default value for this attribute that should be used if the attribute’s element is not present in the document.
• sphinx:document - Mandatory element, must be a child of sphinx:docset. Contains arbitrary other elements with field and attribute values to be indexed, as declared either using sphinx:field and sphinx:attr elements or in the configuration file. The only known attribute is “id” that must contain the unique integer document ID.
• sphinx:killlist - Optional element, child of sphinx:docset. Contains a number of “id” elements whose contents are document IDs to be put into a kill-list of the index. The kill-list is used in multi-index searches to suppress documents found in other indexes of the search

Data definition in source configuration

If the XML doesn’t define a schema, the data types of indexes elements must be defined in the source configuration.

• xmlpipe_field - declares a text field.
• xmlpipe_field_string - declares a text field/string attribute. The column will be both indexed as a text field but also stored as a string attribute.
• xmlpipe_attr_uint - declares an integer attribute
• xmlpipe_attr_timestamp - declares a timestamp attribute
• xmlpipe_attr_bool - declares a boolean attribute
• xmlpipe_attr_float - declares a float attribute
• xmlpipe_attr_bigint - declares a big integer attribute
• xmlpipe_attr_multi - declares a multi-value attribute with integers
• xmlpipe_attr_multi_64 - declares a multi-value attribute with 64bit integers
• xmlpipe_attr_string - declares a string attribute
• xmlpipe_attr_json - declares a JSON attribute

Specific XML source settings

If xmlpipe_fixup_utf8 is set it will enable Manticore-side UTF-8 validation and filtering to prevent XML parser from choking on non-UTF-8 documents. By default this option is disabled.

Under certain occasions it might be hard or even impossible to guarantee that the incoming XMLpipe2 document bodies are in perfectly valid and conforming UTF-8 encoding. For instance, documents with national single-byte encodings could sneak into the stream. libexpat XML parser is fragile, meaning that it will stop processing in such cases. UTF8 fixup feature lets you avoid that. When fixup is enabled, Manticore will preprocess the incoming stream before passing it to the XML parser and replace invalid UTF-8 sequences with spaces.

xmlpipe_fixup_utf8 = 1

Example of XML source without schema in configuration:

source xml_test_1
{
    type = xmlpipe2
    xmlpipe_command = cat /tmp/products_today.xml
}

Example of XML source with schema in configuration:

source xml_test_2
{
    type = xmlpipe2
    xmlpipe_command = cat /tmp/products_today.xml
    xmlpipe_field = subject
    xmlpipe_field = content
    xmlpipe_attr_timestamp = published
    xmlpipe_attr_uint = author_id:16
}