1 <chapter id="proxy-reference">
2 <title>Proxy Reference</title>
3 <section id="proxy-operation">
4 <title>Operating Environment</title>
6 The YAZ proxy is a console program. After startup it spawns
7 a child process (except on Windows or if option -X is given).
8 The child process is the core of the proxy and it handles all
9 communication with clients and servers. The parent process
10 will restart the child process if it dies unexpectedly and report
11 the reason. For options for YAZ proxy,
12 see <xref linkend="proxy-usage"/>.
15 As an option, the proxy may change user identity to a less privileged
19 <section id="proxy-target">
20 <title>Choosing the Backend Server</title>
22 When the proxy receives a Z39.50 Initialize Request from a Z39.50
23 client, it determines the backend server by the following rules:
26 <para>If the <literal>InitializeRequest</literal> PDU from the
28 <link linkend="otherinfo-encoding"><literal>otherInfo</literal></link>
30 <literal>1.2.840.10003.10.1000.81.1</literal>, then the
31 contents of that element specify the server to be used, in the
32 usual YAZ address format (typically
33 <literal>tcp:<parameter>hostname</parameter>:<parameter>port</parameter></literal>)
35 <ulink url="&url.yaz.comstack.addresses;"
36 >the Addresses section of the YAZ manual</ulink>.
41 <para>Otherwise, the Proxy uses the default server, if one was
42 specified in the proxy configuration file. See
43 <xref linkend="proxy-config-target"/>.
48 <para>Otherwise, the Proxy uses the default server, if one was
49 specified on the command-line with the <literal>-t</literal>
54 <para>Otherwise, the proxy closes the connection with
61 If the proxy receives an SRU request, the following rules are used.
64 <para>If default target has Explain information with a
65 <literal>database</literal> that matches the path of the
66 HTTP request of SRU that backend server is used for SRU operation.
71 Otherwise the service will return HTTP 404 (Not found).
77 <section id="proxy-keepalive">
78 <title>Keep-alive Facility</title>
80 The keep-alive is a facility where the proxy keeps the connection to the
81 backend server - even if the client closes the connection to the proxy.
84 If a new or another client connects to the proxy again and requests the
85 same backend it will be reassigned to this backend. In this case, the
86 proxy sends an initialize response directly to the client and an
87 initialize handshake with the backend is omitted.
90 When a client reconnects, query and record caching works better, if the
91 proxy assigns it to the same backend as before. And the result set
92 (if any) is re-used. To achieve this, Index Data defined a session
93 cookie which identifies the backend session.
96 The cookie is defined by the client and is sent as part of the
97 Initialize Request and passed in an
98 <link linkend="otherinfo-encoding"><literal>otherInfo</literal></link>
99 element with OID <literal>1.2.840.10003.10.1000.81.2</literal>.
102 Clients that do not send a cookie as part of the initialize request
103 may still better performance, since the init handshake is saved.
106 Refer to <xref linkend="proxy-config-keepalive"/> on how to setup
107 configuration parameters for keepalive.
112 <section id="query-cache">
113 <title>Query Caching</title>
115 Simple stateless clients often send identical Z39.50 searches
116 in a relatively short period of time (e.g. in order to produce a
117 results-list page, the next page,
118 a single full-record, etc). And for many targets, it's
119 much more expensive to produce a new result set than to
120 reuse an existing one.
123 The proxy tries to solve that by remembering the last query for each
124 backend target, so that if an identical query is received next, it
125 is turned into Present Requests rather than new Search Requests.
129 In a future we release will will probably allows for
130 an arbitrary-sized cache for targets supporting named result sets.
134 You can enable/disable query caching using option -o.
138 <section id="record-cache">
139 <title>Record Caching</title>
141 As an option, the proxy may also cache result set records for the
143 The proxy takes into account the Record Syntax and CompSpec.
144 The CompSpec includes simple element set names as well.
145 By default the cache is 200000 bytes per session.
149 <section id="query-validation">
150 <title>Query Validation</title>
152 The Proxy may also be configured to trap particular attributes in
153 Type-1 queries and send Bib-1 diagnostics back to the client without
154 even consulting the backend target. This facility may be useful if
155 a target does not properly issue diagnostics when unsupported attributes
160 <section id="record-validation">
161 <title>Record Syntax Validation</title>
163 The proxy may be configured to accept, reject or convert records.
164 When accepted, the target passes search/present requests to the
165 backend target under the assumption that the target can honor the
166 request (In fact it may not do that). When a record is rejected because
167 the record syntax is "unsupported" the proxy returns a diagnostic to the
168 client. Finally, the proxy may convert records.
171 The proxy can convert from MARC to MARCXML and thereby offer an
172 XML version of any MARC record as long as it is ISO2709 encoded.
173 If the proxy is compiled with libXSLT support it can also
178 <section id="other-optimizations">
179 <title>Other Optimizations</title>
181 We've had some plans to support global caching of result set records,
182 but this has not yet been implemented.
186 <section id="proxy-config-file">
187 <title>Proxy Configuration File</title>
189 The Proxy may read a configuration file using option
190 <literal>-c</literal> followed by the filename of a config file.
193 The config file is XML based. The YAZ proxy must be compiled
194 with <ulink url="&url.libxml2;">libxml2</ulink> and
195 <ulink url="&url.libxslt;">libXSLT</ulink> support in
196 order for the config file facility to be enabled.
199 See <xref linkend="yazproxy-schema"/> for an XML schema
200 for the configuration.
203 <para>To check for a config file to be well-formed, the yazproxy may
204 be invoked without specifying a listening port, i.e.
206 yazproxy -c myconfig.xml
208 If this does not produce errors, the file is well-formed.
211 <section id="proxy-config-header">
212 <title>Proxy Configuration Header</title>
214 The proxy config file must have a root element called
215 <literal>proxy</literal> and scoped within namespace
216 <literal> xmlns="http://indexdata.dk/yazproxy/schema/0.9/</literal>.
217 All information except an optional XML header must be stored
218 within the <literal>proxy</literal> element.
221 <?xml version="1.0"?>
222 <proxy xmlns="http://indexdata.dk/yazproxy/schema/0.9/">
223 <!-- content here .. -->
227 <section id="proxy-config-target">
228 <title>target</title>
230 The element <literal>target</literal> which may be repeated zero
231 or more times with parent element <literal>proxy</literal> contains
232 information about each backend target.
233 The <literal>target</literal> element have two attributes:
234 <literal>name</literal> which holds the logical name of the backend
235 target (required) and <literal>default</literal> (optional) which
236 (when given) specifies that the backend target is the default target -
237 equivalent to command line option <literal>-t</literal>.
241 <?xml version="1.0"?>
242 <proxy xmlns="http://indexdata.dk/yazproxy/schema/0.9/">
243 <target name="server1" default="1">
244 <!-- description of server1 .. -->
246 <target name="server2">
247 <!-- description of server2 .. -->
253 <section id="proxy-config-url">
256 The <literal>url</literal> which may be repeated one or more times
257 should be the child of the <literal>target</literal> element.
258 The CDATA of <literal>url</literal> is the Z-URL of the backend.
261 Multiple <literal>url</literal> element may be used. In that case, then
262 a client initiates a session, the proxy chooses the URL with the lowest
263 number of active sessions, thereby distributing the load. It is
264 assumed that each URL represents the same database (data).
268 <section id="proxy-config-target-timeout">
269 <title>target-timeout</title>
271 The element <literal>target-timeout</literal> is the child of element
272 <literal>target</literal> and specifies the amount in seconds before
273 a target session is shut down.
276 This can also be specified on the command line by using option
277 <literal>-T</literal>. Refer to OPTIONS in <xref linkend="proxy-usage"/>.
281 <section id="proxy-config-client-timeout">
282 <title>client-timeout</title>
284 The element <literal>client-timeout</literal> is the child of element
285 <literal>target</literal> and specifies the amount in seconds before
286 a client session is shut down.
289 This can also be specified on the command line by using option
290 <literal>-i</literal>. Refer to OPTIONS in <xref linkend="proxy-usage"/>.
294 <section id="proxy-config-keepalive">
295 <title>keepalive</title>
296 <para>The <literal>keepalive</literal> element holds information about
297 the keepalive Z39.50 sessions. Keepalive sessions are proxy-to-backend
298 sessions that is no longer associated with a client session.
300 <para>The <literal>keepalive</literal> element which is the child of
301 the <literal>target</literal>holds two elements:
302 <literal>bandwidth</literal> and <literal>pdu</literal>.
303 The <literal>bandwidth</literal> is the maximum total bytes
304 transferred to/from the target. If a target session exceeds this
305 limit, it is shut down (and no longer kept alive).
306 The <literal>pdu</literal> is the maximum number of requests sent
307 to the target. If a target session exceeds this limit, it is
308 shut down. The idea of these two limits is that avoid very long
309 sessions that use resources in a backend (that leaks!).
312 The following sets maximum number of bytes transferred in a
313 target session to 1 MB and maximum of requests to 400.
316 <bandwidth>1048576</bandwidth>
322 <section id="proxy-config-limit">
325 The <literal>limit</literal> section specifies bandwidth/pdu requests
326 limits for an active session.
327 The proxy records bandwidth/pdu requests during the last 60 seconds
328 (1 minute). The <literal>limit</literal> may include the
329 elements <literal>bandwidth</literal>, <literal>pdu</literal>,
330 <literal>retrieve</literal> and <literal>search</literal>.
331 The <literal>bandwidth</literal>
332 measures the number of bytes transferred within the last minute.
333 The <literal>pdu</literal> is the number of requests in the last
334 minute. The <literal>retrieve</literal> holds the maximum records to
335 which may be retrieved in one Present Request.
336 The <literal>search</literal> is the maximum number of searches
337 within the last minute.
340 If a bandwidth/pdu/search limit is reached the proxy will postpone the
341 requests to the target and wait one or more seconds. The idea of the
342 limit is to ensure that clients that downloads hundreds or thousands of
343 records do not hurt other users.
346 The following sets maximum number of bytes transferred per minute to
347 500Kbytes, maximum number of records retrievals to 40
348 and maximum number of searches to 20.
351 <bandwidth>524288</bandwidth>
352 <retrieve>40</retrieve>
353 <search>20</search>
359 Typically the values in the keepalive section are mugh higher
360 than their equivalent limit counterparts (bandwidth, pdu).
365 <section id="proxy-config-attribute">
366 <title>attribute</title>
368 The <literal>attribute</literal> element specifies accept or reject
369 or a particular attribute type, value pair.
370 Well-behaving targets will reject unsupported attributes on their
371 own. This feature is useful for targets that do not gracefully
372 handle unsupported attributes.
375 Attribute elements may be repeated. The proxy inspects the attribute
376 specifications in the order as specified in the configuration file.
377 When a given attribute specification matches a given attribute list
378 in a query, the proxy takes appropriate action (reject, accept).
381 If no attribute specifications matches the attribute list in a query,
385 The <literal>attribute</literal> element has two required attributes:
386 <literal>type</literal> which is the Attribute Type-1 type, and
387 <literal>value</literal> which is the Attribute Type-1 value.
388 The special value/type <literal>*</literal> matches any attribute
389 type/value. A value may also be specified as a list with each
390 value separated by comma, a value may also be specified as a
391 list: low value - dash - high value.
394 If attribute <literal>error</literal> is given, that holds a
395 Bib-1 diagnostic which is sent to the client if the particular
396 type, value is part of a query.
399 If attribute <literal>error</literal> is not given, the attribute
400 type, value is accepted and passed to the backend target.
403 A target that supports use attributes 1,4, 1000 through 1003 and
404 no other use attributes, could use the following rules:
406 <attribute type="1" value="1,4,1000-1003"/>
407 <attribute type="1" value="*" error="114"/>
411 <section id="proxy-config-syntax">
412 <title>syntax</title>
414 The <literal>syntax</literal> element specifies accept or reject
415 or a particular record syntax request from the client.
418 The <literal>syntax</literal> has one required attribute:
419 <literal>type</literal> which is the Preferred Record Syntax.
422 If attribute <literal>error</literal> is given, that holds a
423 Bib-1 diagnostic which is sent to the client if the particular
424 record syntax is part of a present - or search request.
427 If attribute <literal>error</literal> is not given, the record syntax
428 is accepted and passed to the backend target.
431 If attribute <literal>marcxml</literal> is given, the proxy will
432 perform MARC21 to MARCXML conversion. In this case the
433 <literal>type</literal> should be XML. The proxy will use
434 preferred record syntax USMARC/MARC21 or <literal>backendtype</literal>
435 (if given) against the backend target.
436 For the special case where <literal>backendtype</literal> is
437 <literal>opac</literal> the proxy will convert the OPAC
441 If attribute <literal>backendtype</literal> is given, that holds the
442 record syntax to be transmitted to backend.
445 If attribute <literal>stylesheet</literal> is given, the proxy
446 will convert XML record from server via XSLT. It is important
447 that the content from server is XML. If used in conjunction with
448 attribute <literal>marcxml</literal>, the MARC to MARCXML/OPACXML
449 conversion takes place before the XSLT conversion takes place.
452 If attribute <literal>identifier</literal> is given that is the
453 SRU record schema identifier for the resulting output record (after
454 MARCXML and/or XSLT conversion).
457 If sub element <literal>title</literal> is given (as child element
458 of <literal>syntax</literal>, then that is the official SRU
459 name of the resulting record schema.
462 If sub element <literal>name</literal> is given that is an alias
463 for the record schema identifier. Multiple <literal>name</literal>s
467 <title>MARCXML conversion</title>
468 <para>To accept USMARC and offer MARCXML XML plus Dublin Core (via
469 XSLT conversion) but the following configuration could be used:
472 <target name="mytarget">
474 <syntax type="usmarc"/>
475 <syntax type="xml" marcxml="1"
476 identifier="info:srw/schema/1/marcxml-v1.1"
477 <title>MARCXML<title>
478 <name>marcxml<name>
480 <syntax type="xml" marcxml="1" stylesheet="MARC21slim2SRWDC.xsl"
481 identifier="info:srw/schema/1/dc-v1.1">
482 <title>Dublin Core<title>
485 <syntax type="*" error="238"/>
495 <section id="proxy-config-explain">
496 <title>explain</title>
498 The <literal>explain</literal> element includes Explain information
499 for SRU about the server in the target section. This
500 information must have a <literal>serverInfo</literal> element
501 with a database that this target must be available as (URL path).
504 <explain xmlns="http://explain.z3950.org/dtd/2.0/">
506 <host>myhost.org</host>
508 <database>mydatabase</database>
510 <!-- remaining Explain stuff -->
514 In the above case, the SRU service is available as
515 <literal>http://myhost.org:8000/mydatabase</literal>.
520 <section id="proxy-config-cql2rpn">
521 <title>cql2rpn</title>
523 The content of the <literal>cql2rpn</literal> element specifies
524 the path from the working directory to a CQL-to-RPN conversion
525 file for the server in the target section. This element
526 is required for SRU searches to operate against Z39.50
527 servers that don't support CQL. Most Z39.50 servers only support
528 Type-1/RPN so this is usually required.
531 See YAZ documentation for more information about the
532 <ulink url="&url.yaz.cql2pqf;">CQL to PQF</ulink> conversion.
534 <filename>pqf.properties</filename> in the <filename>etc</filename>
535 (or <replaceable>prefix/share/yazproxy</replaceable>)
536 directory of the YAZ proxy distribution.
540 <section id="proxy-config-preinit">
541 <title>preinit</title>
543 The element <literal>preinit</literal> is the child of element
544 <literal>target</literal> and specifies the number of spare
545 connection to a target. By default no spare connection are
546 created by the proxy. If the proxy uses a target exclusive or
547 a lot, the preinit session will ensure that target sessions
548 have been made before the client makes a connection and will therefore
549 reduce the connect-init handshake dramatically. Never set this to
554 <section id="proxy-config-target-authentication">
555 <title>target-authentication</title>
557 The element <literal>target-authentication</literal> specifies
558 fixed authentication information to be sent to the backend target.
561 This element takes a an attribute <literal>type</literal> which is
562 the authenticatin type to be used..
565 <varlistentry><term><literal>none</literal></term>
568 No authentication. There is no CDATA associated with this.
573 <varlistentry><term><literal>anonymous</literal></term>
576 Anonymous authentication. There is no CDATA associated with this.
581 <varlistentry><term><literal>open</literal></term>
584 Open authentication. The CDATA consists of the
585 open authentication string.
590 <varlistentry><term><literal>idPass</literal></term>
593 IdPass authentication. The CDATA consists of
594 three terms: user, group and password.
601 <section id="proxy-config-target-charset">
602 <title>target-charset</title>
604 The element <literal>target-charset</literal> specifies the
605 native character set that the target uses for queries.
608 If this is specified the proxy will act as a Z39.50 server
609 supporting character set negotiation. And in SRU mode
610 it will convert from UTF-8 (UNICODE) to this native character
615 <section id="proxy-config-max-clients">
616 <title>max-clients</title>
618 The element <literal>max-clients</literal> is the child of element
619 <literal>proxy</literal> and specifies the total number of
620 allowed connections to targets (all targets). If this limit
621 is reached the proxy will close the least recently used connection.
624 Note, that many Unix systems impose a system on the number of
625 open files allowed in a single process, typically in the
626 range 256 (Solaris) to 1024 (Linux).
627 The proxy uses 2 sockets per session + a few files
628 for logging. As a rule of thumb, ensure that 2*max-clients + 5
629 can be opened by the proxy process.
633 Using the <ulink url="&url.bash;">bash</ulink> shell, you can set
635 <literal>ulimit -n</literal><replaceable>no</replaceable>.
636 Use <literal>ulimit -a</literal> to display limits.
641 <section id="proxy-config-log">
644 The element <literal>log</literal> is the child of element
645 <literal>proxy</literal> and specifies what to be logged by the
649 Specify the log file with command-line option <literal>-l</literal>.
652 The text of the <literal>log</literal> element is a sequence of
653 options separated by white space. See the table below:
654 <table frame="top"><title>Logging options</title>
656 <colspec colwidth="1*"/>
657 <colspec colwidth="2*"/><thead>
659 <entry>Option</entry>
660 <entry>Description</entry>
665 <entry><literal>client-apdu</literal></entry>
667 Log APDUs as reported by YAZ for the
668 communication between the client and the proxy.
669 This facility is equivalent to the APDU logging that
670 happens when using option <literal>-a</literal>, however
671 this tells the proxy to log in the same file as given
672 by <literal>-l</literal>.
676 <entry><literal>server-apdu</literal></entry>
678 Log APDUs as reported by YAZ for the
679 communication between the proxy and the server (backend).
683 <entry><literal>clients-requests</literal></entry>
685 Log a brief description about requests transferred between
686 the client and the proxy. The name of the request and the size
687 of the APDU is logged.
691 <entry><literal>server-requests</literal></entry>
693 Log a brief description about requests transferred between
694 the proxy and the server (backend). The name of the request
695 and the size of the APDU is logged.
699 <entry><literal>client-ip</literal></entry>
701 Log the client IP for each log entry. By default, the client IP
702 is only logged when a new session starts.
710 To log communication in details between the proxy and the backend, th
711 following configuration could be used:
713 <target name="mytarget">
714 <log>server-apdu server-requests</log>
721 <section id="proxy-max-connect">
722 <title>max-connect</title>
724 The element <literal>max-connect</literal> is a child of element
725 <literal>proxy</literal> and specifies the maximum number
726 of connections to be initiated within the last minute (or
727 value of <link linkend="proxy-period-connect">period-connect</link>.
730 If the maximum number is reached the proxy will terminate the
731 just initiated session (connection terminated).
735 <section id="proxy-limit-connect">
736 <title>limit-connect</title>
738 The element <literal>max-connect</literal> is a child of element
739 <literal>proxy</literal> and specifies the limit of number
740 of connections to be initiated within the last minute (or
741 value of <link linkend="proxy-period-connect">period-connect</link>.
744 If the maximum number is reached the proxy delays the first operation
745 in the session by one second.
749 <section id="proxy-period-connect">
750 <title>period-connect</title>
752 The element <literal>period-connect</literal> is a child of element
753 <literal>proxy</literal> and specifies period - in the number of seconds
754 that <link linkend="proxy-limit-connect">limit-connect</link> and
755 <link linkend="proxy-max-connect">max-connect</link>
756 should measure connections.
759 If <literal>period-connect</literal> is omitted, 60 seconds is used.
763 <section id="proxy-docpath">
764 <title>docpath</title>
766 The element <literal>docpath</literal> is a child of element
767 <literal>proxy</literal> and specifies an allowed HTTP path
768 for local file access. Using <literal>docpath</literal> the
769 proxy may return static file content.
772 The value of docpath both serves as a HTTP path prefix
773 <emphasis>and</emphasis> as a local file prefix.
774 If a value of <literal>etc</literal> is used only URLs with the
775 prefix <literal>/etc/</literal> results in a local file access to the
776 directory <literal>etc</literal> within the working directory
781 Care has been taken to ensure that hostile URLs are rejected - including
782 strings such as <literal>..</literal> and <literal>/</literal> (absolute
789 <section id="proxy-usage">
790 <title>Proxy Manual Pages</title>
791 <refentry id="yazproxy-man">
796 <section id="otherinfo-encoding">
797 <title>OtherInformation Encoding</title>
799 The proxy uses the OtherInformation definition to carry
800 information about the target address and cookie.
803 OtherInformation ::= [201] IMPLICIT SEQUENCE OF SEQUENCE{
804 category [1] IMPLICIT InfoCategory OPTIONAL,
806 characterInfo [2] IMPLICIT InternationalString,
807 binaryInfo [3] IMPLICIT OCTET STRING,
808 externallyDefinedInfo [4] IMPLICIT EXTERNAL,
809 oid [5] IMPLICIT OBJECT IDENTIFIER}}
811 InfoCategory ::= SEQUENCE{
812 categoryTypeId [1] IMPLICIT OBJECT IDENTIFIER OPTIONAL,
813 categoryValue [2] IMPLICIT INTEGER}
816 The <literal>categoryTypeId</literal> is either
817 OID 1.2.840.10003.10.1000.81.1, 1.2.840.10003.10.1000.81.2
818 for proxy target and proxy cookie respectively. The
819 <literal>categoryValue</literal> is set to 1.
820 The value proxy and cookie is stored in element
821 <literal>characterInfo</literal> of the <literal>information</literal>
825 <section id="yazproxy-schema">
826 <title>YAZ Proxy Configuration Schema</title>
828 Here an XML Schema for the YAZ proxy configuration file.
829 The schema, <filename>yazproxy.xsd</filename> is located in sub
830 directory <filename>etc</filename> of the distribution.
833 <?xml version="1.0"?>
834 <!-- XML Schema for YAZ proxy config file.
835 $Id: reference.xml,v 1.20 2006-06-14 10:12:26 adam Exp $
838 xmlns:xs="http://www.w3.org/2001/XMLSchema"
839 xmlns:exp="http://explain.z3950.org/dtd/2.0/"
840 xmlns="http://indexdata.dk/yazproxy/schema/0.9/"
841 targetNamespace="http://indexdata.dk/yazproxy/schema/0.9/"
843 <xs:import namespace="http://explain.z3950.org/dtd/2.0/"
844 schemaLocation="zeerex-2.0.xsd"/>
845 <xs:element name="proxy">
848 <xs:element ref="target" minOccurs="0" maxOccurs="unbounded"/>
849 <xs:element ref="max-clients" minOccurs="0"/>
850 <xs:element ref="log" minOccurs="0"/>
851 <xs:element ref="module" minOccurs="0"/>
856 <xs:element name="target">
859 <xs:element ref="url" minOccurs="0" maxOccurs="unbounded"/>
860 <xs:element ref="target-timeout" minOccurs="0"/>
861 <xs:element ref="client-timeout" minOccurs="0"/>
862 <xs:element ref="keepalive" minOccurs="0"/>
863 <xs:element ref="limit" minOccurs="0"/>
864 <xs:element ref="attribute" minOccurs="0" maxOccurs="unbounded"/>
865 <xs:element ref="syntax" minOccurs="0" maxOccurs="unbounded"/>
866 <xs:element ref="preinit" minOccurs="0"/>
867 <xs:element ref="exp:explain" minOccurs="0"/>
868 <xs:element ref="cql2rpn" minOccurs="0"/>
869 <xs:element ref="target-authentication" minOccurs="0"/>
870 <xs:element ref="client-authentication" minOccurs="0"/>
871 <xs:element ref="negotiation-charset" minOccurs="0"/>
872 <xs:element ref="negotiation-lang" minOccurs="0"/>
874 <xs:attribute name="default" type="xs:string" use="optional"/>
875 <xs:attribute name="name" type="xs:string"/>
876 <xs:attribute name="database" type="xs:string"/>
880 <xs:element name="url" type="xs:string"/>
881 <xs:element name="target-timeout" type="xs:integer"/>
882 <xs:element name="client-timeout" type="xs:integer"/>
883 <xs:element name="bandwidth" type="xs:integer"/>
884 <xs:element name="pdu" type="xs:integer"/>
885 <xs:element name="retrieve" type="xs:integer"/>
886 <xs:element name="preinit" type="xs:integer"/>
887 <xs:element name="cql2rpn" type="xs:string"/>
888 <xs:element name="target-authentication">
891 <xs:extension base="xs:string">
892 <xs:attribute name="type" type="xs:string"/>
898 <xs:element name="client-authentication">
901 <xs:extension base="xs:string">
902 <xs:attribute name="module" type="xs:string"/>
903 <xs:attribute name="args" type="xs:string"/>
909 <xs:element name="negotiation-charset" type="xs:string"/>
910 <xs:element name="negotiation-lang" type="xs:string"/>
912 <xs:element name="keepalive">
915 <xs:element ref="bandwidth" minOccurs="0"/>
916 <xs:element ref="pdu" minOccurs="0"/>
920 <xs:element name="limit">
923 <xs:element ref="bandwidth" minOccurs="0"/>
924 <xs:element ref="pdu" minOccurs="0"/>
925 <xs:element ref="retrieve" minOccurs="0"/>
930 <xs:element name="attribute">
932 <xs:attribute name="type" type="xs:string"/>
933 <xs:attribute name="value" type="xs:string"/>
934 <xs:attribute name="error" type="xs:integer"/>
938 <xs:element name="syntax">
941 <xs:element ref="title" minOccurs="0"/>
942 <xs:element ref="name" minOccurs="0" maxOccurs="unbounded"/>
944 <xs:attribute name="error" type="xs:string" />
945 <xs:attribute name="type" type="xs:string" />
946 <xs:attribute name="marcxml" type="xs:string" />
947 <xs:attribute name="identifier" type="xs:string" />
948 <xs:attribute name="stylesheet" type="xs:string" />
949 <xs:attribute name="backendtype" type="xs:string" />
950 <xs:attribute name="backendcharset" type="xs:string" />
951 <xs:attribute name="usemarconstage1" type="xs:string" />
952 <xs:attribute name="usemarconstage2" type="xs:string" />
956 <xs:element name="title" type="xs:string"/>
957 <xs:element name="name" type="xs:string"/>
959 <xs:element name="max-clients" type="xs:integer"/>
960 <xs:element name="log" type="xs:string"/>
961 <xs:element name="module" type="xs:string"/>
969 <!-- Keep this comment at the end of the file
974 sgml-minimize-attributes:nil
975 sgml-always-quote-attributes:t
978 sgml-parent-document: "yazproxy.xml"
979 sgml-local-catalogs: nil
980 sgml-namecase-general:t