Hi,
Two further questions:
1. What's the cleanest way to get a log containing the actual query strings? AFAIU BaseX doesn't use any logging framework and the BaseXServlet.service has a finally block that prints the request headers (if Prop.debug is enabled) but not the request body. I thought about writing my own Filter for that purpose.
2. I've been trying to update BaseX to the latest snapshot, but the queries generated by my application, that used to work with 7.2.1 and 7.3 don't seem to work now. The body of a POST looks like this (\n means a newline character):
<?xml version="1.0" encoding="UTF-8"?>\n <command xmlns="http://basex.org/rest"><text><![CDATA[\n ADD TO 5d03ebad-dc6a-492c-9527-bd2ce3830080\n <tx id="5d03ebad-dc6a-492c-9527-bd2ce3830080"\n dbId=""\n xmlns="http://our.namespace.com/xmlns/"\n xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"\n xmlns:xs="http://www.w3.org/2001/XMLSchema"\n <commit />\n <skip />\n </tx>\n \n ]]></text></command>
Now the question is what's wrong with this query. I get a 400 Bad Request response with the following error message.
Stopped at line 1, column 43:\n Syntax: ADD (TO [path]) [input]\n Add resource to database.\n \n Adds [input] as [path] to the database.\n
As I said this used to work with 7.3. I tried to diff the StringParser class between 7.3 and the current trunk. It seems to use the InputParser on a single line and not on the entire query. I can't spot anything that would explain this behaviour though.
All kinds of comments welcome.
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
----- Ursprüngliche Mail ----- Von: "Antoni Mylka" amy@basis06.ch An: "Christian Grün" christian.gruen@gmail.com Gesendet: Montag, 12. November 2012 15:42:42 Betreff: Re: [basex-talk] Database corruption
Dear Christian,
Thanks for the tip. Will fix the logging settings and retest with the latest snapshot.
Best regards,
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
----- Ursprüngliche Mail ----- Von: "Christian Grün" christian.gruen@gmail.com An: "Antoni Mylka" amy@basis06.ch CC: "basex-talk" basex-talk@mailman.uni-konstanz.de Gesendet: Montag, 12. November 2012 15:34:23 Betreff: Re: [basex-talk] Database corruption
Dear Antoni,
without having read all the elaborate details in your mail (thanks), I would strongly advise to try the latest stable 7.5 snapshot [1], which contains some important improvements reg. concurrent updates. I'm well aware that it feels inconvenient to use beta releases in productive environments, but the current version of 7.5 is very stable, and will be released soon without any major enhancements or legacy issues.
Hope this helps, Christian
[1] http://files.basex.org/releases/latest/ ___________________________
On Mon, Nov 12, 2012 at 3:30 PM, Antoni Mylka amy@basis06.ch wrote:
Hi,
We're developing an application that uses BaseX. In our tests, the application works properly for a couple of hours, makes queries to BaseX adds and removes data. Then suddenly some BaseX request will return the HTTP 500 response. From that point on all queries that make modifications in the database end in an error and the entire system grinds to a screeching halt. One of the experiments ran for four days, then we examined the access log to see that only the first 6 hours were OK, after that all BaseX queries would end in error.
I'm going to investigate and will try to come up with as detailed a description of the issue as possible. For now the things I know are:
- In our experiment, the application would make about 80000 successful queries over a period of 6 hours. Then it would get the first 500 error.
- Afterwards it "seems" that the queries which don't modify anything end with 200, while all the modification queries end with a 500 error. That's to be confirmed.
- BaseX 7.2.1 runs in a war deployed on Tomcat 7.0.32 on a linux system.
- The access logs don't show anything interesting.
- The catalina.out that shows the Tomcat standard output contains hundreds of exceptions of the following kind:
Exception in thread "Thread-78197" java.lang.RuntimeException: Data Access out of bounds [pre:1422612, indexSize:5540, access:5540 > 5539] at org.basex.util.Util.notexpected(Util.java:55) at org.basex.io.random.TableDiskAccess.cursor(TableDiskAccess.java:478) at org.basex.io.random.TableDiskAccess.read5(TableDiskAccess.java:211) at org.basex.data.Data.textOff(Data.java:432) at org.basex.data.DiskData.text(DiskData.java:228) at org.basex.index.value.DiskValues.get(DiskValues.java:295) at org.basex.index.value.UpdatableDiskValues.index(UpdatableDiskValues.java:133) at org.basex.data.DiskData$1.run(DiskData.java:461)
The thread name is different every time and the numbers in square brackets are also different. I don't see any patterns (yet). 6. BaseX is accessed from a single thread in a single application. AFAIK there are no concurrent requests, though that is to be confirmed. 7. The GC log shows that basex stays below 100M of used heap, which is well below the allotted Xmx setting of 2G. 8. We did three experiments and the same effect has been observed in all three, albeit after different periods of time: (59K queries and 4:25 hours, 37K queries and 2:56 hours, 76.8K queries and 6 hours).
Things I intend to do:
- Set up proper logging for BaseX, so that these errors don't end up in catalina.out, but in the proper log file.
- Catch the first offending query, see if there is anything unusual about it. It certainly doesn't differ much from the successful queries. It simply updates the BaseX state to keep it in sync with an external data source. All the update queries are generated by the same template and there have been hundreds of successful ones before the first error occurs.
- Manipulate the log settings, to see if it's possible to get something more meaningful out of them.
- Try newer versions: 7.3 and the current trunk.
I've seen emails similar about "Data Access out of bounds" but they don't seem relevant.
As I said, I'll try to come up with more information, but if the error or the stack trace looks familiar - I'd be grateful for pointers.
Thanks in advance,
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
BaseX-Talk mailing list BaseX-Talk@mailman.uni-konstanz.de https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk
Hi,
I debugged what goes on inside StringParser in the command posted earlier. It seems that the parser makes an assumption that the ADD command should fit on a single line. It works OK when I replace the newlines with spaces in the XML content to be added. It seems to me like a rather serious bug. Am I missing something obvious? I would really like to be able to push multi-line content to BaseX. If ADD TO is not the way to do that, then what is?
The splitting of a command string into single lines has been done in
https://github.com/BaseXdb/basex/commit/fffde7fa12a7cec6882f603638ea3e3ef366...
As far as I understand this change was about making the StringParser support .bxs scripts that can contain more than one command on each line. The distinction between a .bxs script and a "normal" command is done via the "single" flag. For normal commands "single" is set to true. Perhaps the easiest solution would be to keep the current processing if single is false, but if single is true, just use the whole string. I tried to create a patch that does it. Is the patch I attached worth anything? It seems to solve my immediate problem with the particular query I posted. I really don't understand much about BaseX codebase (or about git for that matter :) ) Please review.
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
----- Ursprüngliche Mail ----- Von: "Antoni Mylka" amy@basis06.ch An: "basex-talk" basex-talk@mailman.uni-konstanz.de Gesendet: Montag, 12. November 2012 19:17:35 Betreff: Re: [basex-talk] Database corruption
Hi,
Two further questions:
1. What's the cleanest way to get a log containing the actual query strings? AFAIU BaseX doesn't use any logging framework and the BaseXServlet.service has a finally block that prints the request headers (if Prop.debug is enabled) but not the request body. I thought about writing my own Filter for that purpose.
2. I've been trying to update BaseX to the latest snapshot, but the queries generated by my application, that used to work with 7.2.1 and 7.3 don't seem to work now. The body of a POST looks like this (\n means a newline character):
<?xml version="1.0" encoding="UTF-8"?>\n <command xmlns="http://basex.org/rest"><text><![CDATA[\n ADD TO 5d03ebad-dc6a-492c-9527-bd2ce3830080\n <tx id="5d03ebad-dc6a-492c-9527-bd2ce3830080"\n dbId=""\n xmlns="http://our.namespace.com/xmlns/"\n xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"\n xmlns:xs="http://www.w3.org/2001/XMLSchema"\n <commit />\n <skip />\n </tx>\n \n ]]></text></command>
Now the question is what's wrong with this query. I get a 400 Bad Request response with the following error message.
Stopped at line 1, column 43:\n Syntax: ADD (TO [path]) [input]\n Add resource to database.\n \n Adds [input] as [path] to the database.\n
As I said this used to work with 7.3. I tried to diff the StringParser class between 7.3 and the current trunk. It seems to use the InputParser on a single line and not on the entire query. I can't spot anything that would explain this behaviour though.
All kinds of comments welcome.
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
Antoni, thanks in advance! Be sure I'll have a look at this later today.. Christian Am 13.11.2012 14:28 schrieb "Antoni Mylka" amy@basis06.ch:
Hi,
I debugged what goes on inside StringParser in the command posted earlier. It seems that the parser makes an assumption that the ADD command should fit on a single line. It works OK when I replace the newlines with spaces in the XML content to be added. It seems to me like a rather serious bug. Am I missing something obvious? I would really like to be able to push multi-line content to BaseX. If ADD TO is not the way to do that, then what is?
The splitting of a command string into single lines has been done in
https://github.com/BaseXdb/basex/commit/fffde7fa12a7cec6882f603638ea3e3ef366...
As far as I understand this change was about making the StringParser support .bxs scripts that can contain more than one command on each line. The distinction between a .bxs script and a "normal" command is done via the "single" flag. For normal commands "single" is set to true. Perhaps the easiest solution would be to keep the current processing if single is false, but if single is true, just use the whole string. I tried to create a patch that does it. Is the patch I attached worth anything? It seems to solve my immediate problem with the particular query I posted. I really don't understand much about BaseX codebase (or about git for that matter :) ) Please review.
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
----- Ursprüngliche Mail ----- Von: "Antoni Mylka" amy@basis06.ch An: "basex-talk" basex-talk@mailman.uni-konstanz.de Gesendet: Montag, 12. November 2012 19:17:35 Betreff: Re: [basex-talk] Database corruption
Hi,
Two further questions:
- What's the cleanest way to get a log containing the actual query
strings? AFAIU BaseX doesn't use any logging framework and the BaseXServlet.service has a finally block that prints the request headers (if Prop.debug is enabled) but not the request body. I thought about writing my own Filter for that purpose.
- I've been trying to update BaseX to the latest snapshot, but the
queries generated by my application, that used to work with 7.2.1 and 7.3 don't seem to work now. The body of a POST looks like this (\n means a newline character):
<?xml version="1.0" encoding="UTF-8"?>\n
<command xmlns="http://basex.org/rest"><text><![CDATA[\n ADD TO 5d03ebad-dc6a-492c-9527-bd2ce3830080\n <tx id="5d03ebad-dc6a-492c-9527-bd2ce3830080"\n dbId=""\n xmlns="http://our.namespace.com/xmlns/"\n xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"\n xmlns:xs="http://www.w3.org/2001/XMLSchema"\n <commit />\n <skip />\n </tx>\n \n ]]></text></command>
Now the question is what's wrong with this query. I get a 400 Bad Request response with the following error message.
Stopped at line 1, column 43:\n Syntax: ADD (TO [path]) [input]\n Add resource to database.\n \n Adds [input] as [path] to the database.\n
As I said this used to work with 7.3. I tried to diff the StringParser class between 7.3 and the current trunk. It seems to use the InputParser on a single line and not on the entire query. I can't spot anything that would explain this behaviour though.
All kinds of comments welcome.
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business _______________________________________________ BaseX-Talk mailing list BaseX-Talk@mailman.uni-konstanz.de https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk
Hi Antoni,
to start bottom up.. It feels as if you already know our code base quite well ;) Your description of the bug and the reasons for the changes in the code were absolutely right. I didn't manage to merge your patch out-of-box, but I adopted the general idea [1], which means the problem should now be resolved.
By the way, we are planning to add support for our XML command syntax to the REST API [2]. Beside that, you could also use the PUT method in order to add documents to a database [3]; but I assume you already though about that anyway.
Your feedback is welcome, thanks again, Christian
[1] https://github.com/BaseXdb/basex/commit/d4abedd2080d98897533ed3c3329ac7030c5... [2] https://github.com/BaseXdb/basex/issues/559 [3] http://docs.basex.org/wiki/REST#PUT_Requests _________________________________________
I debugged what goes on inside StringParser in the command posted earlier. It seems that the parser makes an assumption that the ADD command should fit on a single line. It works OK when I replace the newlines with spaces in the XML content to be added. It seems to me like a rather serious bug. Am I missing something obvious? I would really like to be able to push multi-line content to BaseX. If ADD TO is not the way to do that, then what is?
The splitting of a command string into single lines has been done in
https://github.com/BaseXdb/basex/commit/fffde7fa12a7cec6882f603638ea3e3ef366...
As far as I understand this change was about making the StringParser support .bxs scripts that can contain more than one command on each line. The distinction between a .bxs script and a "normal" command is done via the "single" flag. For normal commands "single" is set to true. Perhaps the easiest solution would be to keep the current processing if single is false, but if single is true, just use the whole string. I tried to create a patch that does it. Is the patch I attached worth anything? It seems to solve my immediate problem with the particular query I posted. I really don't understand much about BaseX codebase (or about git for that matter :) ) Please review.
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
----- Ursprüngliche Mail ----- Von: "Antoni Mylka" amy@basis06.ch An: "basex-talk" basex-talk@mailman.uni-konstanz.de Gesendet: Montag, 12. November 2012 19:17:35 Betreff: Re: [basex-talk] Database corruption
Hi,
Two further questions:
What's the cleanest way to get a log containing the actual query strings? AFAIU BaseX doesn't use any logging framework and the BaseXServlet.service has a finally block that prints the request headers (if Prop.debug is enabled) but not the request body. I thought about writing my own Filter for that purpose.
I've been trying to update BaseX to the latest snapshot, but the queries generated by my application, that used to work with 7.2.1 and 7.3 don't seem to work now. The body of a POST looks like this (\n means a newline character):
<?xml version="1.0" encoding="UTF-8"?>\n
<command xmlns="http://basex.org/rest"><text><![CDATA[\n ADD TO 5d03ebad-dc6a-492c-9527-bd2ce3830080\n <tx id="5d03ebad-dc6a-492c-9527-bd2ce3830080"\n dbId=""\n xmlns="http://our.namespace.com/xmlns/"\n xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"\n xmlns:xs="http://www.w3.org/2001/XMLSchema"\n <commit />\n <skip />\n </tx>\n \n ]]></text></command>
Now the question is what's wrong with this query. I get a 400 Bad Request response with the following error message.
Stopped at line 1, column 43:\n Syntax: ADD (TO [path]) [input]\n Add resource to database.\n \n Adds [input] as [path] to the database.\n
As I said this used to work with 7.3. I tried to diff the StringParser class between 7.3 and the current trunk. It seems to use the InputParser on a single line and not on the entire query. I can't spot anything that would explain this behaviour though.
All kinds of comments welcome.
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
BaseX-Talk mailing list BaseX-Talk@mailman.uni-konstanz.de https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk
Hi Christian,
Thanks for the quick response. Just started another test with the latest snapshot.
In the meantime I tried a patched version yesterday and stumbled upon another issue. One of our queries did something like this (snippet simplified for readability):
for $item in /somepath/someitemelement let $lmd as xs:dateTime := $item/value[@xsi:type="xs:dateTime"] let $dur := $now - $lmd where $dur > $itemMaxAge return $dur }
<somepath> <someitemelement> <value xsi:type="xs:dateTime">2012-11-14T13:02:23Z</value> </someitemelement> </somepath>
Now in 7.2.1 and in 7.3 the construct above would work i.e. * let $lmd as xs:dateTime was OK * the conversion from the <value> element to a dateTime value worked
In the current snapshot I had to change that query. Things that worked are: * let $lmd := xs:dateTime($item/value[@xsi:type="xs:dateTime"]/text()) * let $lmd := $item/value[@xsi:type="xs:dateTime"] cast as xs:dateTime
Now questions: 1. Was the query above wrong? 2. Which of the suggested new versions will be the fastest? The first "feels" like a double cast dateTime->string->dateTime. 3. What is the cleanest way to get a log with actual queries. I use tcpdump now, which is rather ugly. I tried the standard Tomcat's RequestDumperFilter, but it prints all the request information *apart* from the body. Do I have to write my own filter, as the guy on Stackoverlow did:
http://stackoverflow.com/questions/1528628/logging-payload-of-posts-to-tomca...
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
----- Ursprüngliche Mail ----- Von: "Christian Grün" christian.gruen@gmail.com An: "Antoni Mylka" amy@basis06.ch CC: "basex-talk" basex-talk@mailman.uni-konstanz.de Gesendet: Mittwoch, 14. November 2012 00:34:47 Betreff: Re: [basex-talk] Database corruption
Hi Antoni,
to start bottom up.. It feels as if you already know our code base quite well ;) Your description of the bug and the reasons for the changes in the code were absolutely right. I didn't manage to merge your patch out-of-box, but I adopted the general idea [1], which means the problem should now be resolved.
By the way, we are planning to add support for our XML command syntax to the REST API [2]. Beside that, you could also use the PUT method in order to add documents to a database [3]; but I assume you already though about that anyway.
Your feedback is welcome, thanks again, Christian
[1] https://github.com/BaseXdb/basex/commit/d4abedd2080d98897533ed3c3329ac7030c5... [2] https://github.com/BaseXdb/basex/issues/559 [3] http://docs.basex.org/wiki/REST#PUT_Requests
Hi,
The test runs and I still get exceptions. They are different from those in 7.2.1 and don't happen every time, but are still scary.
Improper use? Potential bug? Your feedback is welcome: Contact: basex-talk@mailman.uni-konstanz.de Version: BaseX 7.5 beta Java: Sun Microsystems Inc., 1.6.0_27 OS: Linux, amd64 Stack Trace: java.lang.ArrayIndexOutOfBoundsException: 2147483647 org.basex.io.random.TableDiskAccess.cursor(TableDiskAccess.java:486) org.basex.io.random.TableDiskAccess.read5(TableDiskAccess.java:211) org.basex.data.Data.textOff(Data.java:420) org.basex.data.DiskData.text(DiskData.java:234) org.basex.index.value.DiskValues.readKeyAt(DiskValues.java:285) org.basex.index.value.DiskValues.get(DiskValues.java:441) org.basex.index.value.UpdatableDiskValues.delete(UpdatableDiskValues.java:135) org.basex.data.DiskData.indexDelete(DiskData.java:427) org.basex.data.Data.delete(Data.java:608) org.basex.data.atomic.Replace.apply(Replace.java:35) org.basex.data.atomic.AtomicUpdateList.applyStructuralUpdates(AtomicUpdateList.java:310) org.basex.data.atomic.AtomicUpdateList.execute(AtomicUpdateList.java:298) org.basex.query.up.DatabaseUpdates.apply(DatabaseUpdates.java:175) org.basex.query.up.ContextModifier.apply(ContextModifier.java:88) org.basex.query.up.Updates.apply(Updates.java:122) org.basex.query.QueryContext.update(QueryContext.java:273) org.basex.query.QueryContext.value(QueryContext.java:258) org.basex.query.QueryContext.iter(QueryContext.java:243) org.basex.query.QueryProcessor.iter(QueryProcessor.java:76) org.basex.server.QueryListener.execute(QueryListener.java:127) org.basex.server.LocalQuery.execute(LocalQuery.java:53) org.basex.http.rest.RESTQuery.query(RESTQuery.java:93) org.basex.http.rest.RESTQuery.run(RESTQuery.java:47) org.basex.http.rest.RESTPost.run(RESTPost.java:107) org.basex.http.rest.RESTServlet.run(RESTServlet.java:14) org.basex.http.BaseXServlet.service(BaseXServlet.java:39)
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
----- Ursprüngliche Mail ----- Von: "Antoni Mylka" amy@basis06.ch An: "basex-talk" basex-talk@mailman.uni-konstanz.de Gesendet: Mittwoch, 14. November 2012 13:15:01 Betreff: Re: [basex-talk] Database corruption
Hi Christian,
Thanks for the quick response. Just started another test with the latest snapshot.
The test runs and I still get exceptions. They are different from those in 7.2.1 and don't happen every time, but are still scary.
I agree, this looks a little bit frightening.. I guess it won’t be easy, but it would be great if you manage to create a reproducible test case. ________________________________________
Improper use? Potential bug? Your feedback is welcome: Contact: basex-talk@mailman.uni-konstanz.de Version: BaseX 7.5 beta Java: Sun Microsystems Inc., 1.6.0_27 OS: Linux, amd64 Stack Trace: java.lang.ArrayIndexOutOfBoundsException: 2147483647 org.basex.io.random.TableDiskAccess.cursor(TableDiskAccess.java:486) org.basex.io.random.TableDiskAccess.read5(TableDiskAccess.java:211) org.basex.data.Data.textOff(Data.java:420) org.basex.data.DiskData.text(DiskData.java:234) org.basex.index.value.DiskValues.readKeyAt(DiskValues.java:285) org.basex.index.value.DiskValues.get(DiskValues.java:441) org.basex.index.value.UpdatableDiskValues.delete(UpdatableDiskValues.java:135) org.basex.data.DiskData.indexDelete(DiskData.java:427) org.basex.data.Data.delete(Data.java:608) org.basex.data.atomic.Replace.apply(Replace.java:35) org.basex.data.atomic.AtomicUpdateList.applyStructuralUpdates(AtomicUpdateList.java:310) org.basex.data.atomic.AtomicUpdateList.execute(AtomicUpdateList.java:298) org.basex.query.up.DatabaseUpdates.apply(DatabaseUpdates.java:175) org.basex.query.up.ContextModifier.apply(ContextModifier.java:88) org.basex.query.up.Updates.apply(Updates.java:122) org.basex.query.QueryContext.update(QueryContext.java:273) org.basex.query.QueryContext.value(QueryContext.java:258) org.basex.query.QueryContext.iter(QueryContext.java:243) org.basex.query.QueryProcessor.iter(QueryProcessor.java:76) org.basex.server.QueryListener.execute(QueryListener.java:127) org.basex.server.LocalQuery.execute(LocalQuery.java:53) org.basex.http.rest.RESTQuery.query(RESTQuery.java:93) org.basex.http.rest.RESTQuery.run(RESTQuery.java:47) org.basex.http.rest.RESTPost.run(RESTPost.java:107) org.basex.http.rest.RESTServlet.run(RESTServlet.java:14) org.basex.http.BaseXServlet.service(BaseXServlet.java:39)
-- Antoni Myłka Software Engineer
basis06 AG, Birkenweg 61, CH-3013 Bern - Fon +41 31 311 32 22 http://www.basis06.ch - source of smart business
----- Ursprüngliche Mail ----- Von: "Antoni Mylka" amy@basis06.ch An: "basex-talk" basex-talk@mailman.uni-konstanz.de Gesendet: Mittwoch, 14. November 2012 13:15:01 Betreff: Re: [basex-talk] Database corruption
Hi Christian,
Thanks for the quick response. Just started another test with the latest snapshot.
BaseX-Talk mailing list BaseX-Talk@mailman.uni-konstanz.de https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk
Hi Antoni,
Now questions:
- Was the query above wrong?
yes, it was. We've further strengthened our type checks by introducing a distinction between casts and sequence type matchings, as demanded by the spec. In a nutshell: the type extension "as xs:dateTime" checks only if a value can be treated as item of type xs:dateTime, but it does not perform a cast.
- let $lmd := xs:dateTime($item/value[@xsi:type="xs:dateTime"]/text())
- let $lmd := $item/value[@xsi:type="xs:dateTime"] cast as xs:dateTime
- Which of the suggested new versions will be the fastest? The first "feels" like a double cast dateTime->string->dateTime.
Both variants should take pretty much the same time, as "cast as" will be evaluated the same way as xs:dateTime(). In the first variant, however, you can get rid of the text() step.
- What is the cleanest way to get a log with actual queries. I use tcpdump now, which is rather ugly. I tried the standard Tomcat's RequestDumperFilter, but it prints all the request information *apart* from the body. Do I have to write my own filter, as the guy on Stackoverlow did:
http://stackoverflow.com/questions/1528628/logging-payload-of-posts-to-tomca...
This would surely be an option. You may as well have a look into the server logs, found at data/.logs. It’s particularly useful for ordinary client requests and RESTXQ calls, but it could be enriched with some additional information if that looks useful.
Hope this helps, Christian
basex-talk@mailman.uni-konstanz.de
-
Antoni Mylka -
Christian Grün