On 29/03/2023 12:56, Rob @ DNR wrote:
Yes, you can filter these out, the logger in question is the class name shown,
the log4j configuration will need to reference that via its fully qualified
name i.e. org.apache.jena.sparql.engine.iterator.QueryIterFilterExpr and set it
to ERROR/OFF to suppress these warnings
Issuing millions of instances of the same identical warning certainly seems
like a bug to me, especially since this is elicited by query input it could
potentially be abused as a DoS attack vector.
Rob
From: Mikael Pesonen <[email protected]>
Date: Wednesday, 29 March 2023 at 10:22
To: [email protected] <[email protected]>
Subject: Re: Strategies to avoid log flooding
Below is the log, so is it possible to filter just these out?
Unfortunately I don't recall the exact regex but it was related to
escaping parentheses, so maybe this or with one back slash:
...
VALUES ?class_label { " \\(häiriö\\)" " \\(löydös\\)" " \\(toimenpide\\)" }
?concept rdfs:label ?fsnl FILTER (REGEX(?fsnl, $class_label)) .
That does not align with the log message which says the pattern is "
\\(häiriö\\)"@fi
meaning $class_label is @fi.
Use str() to get the lexical part.
The regex is potentially different every call. So the regex is compiled
every call. (If it's the same, a constant, it is compiled once.)
Here, write as three calls, one per constant.
Or use CONTAINS, because a regex is unnecessary in this case.
Andy
...
So this is a bug not a feature and can be corrected?
Mar 27 13:13:33 insight-terms java[2512289]: [2023-03-27 13:13:33]
QueryIterFilterExpr WARN Expression Exception in (regex ?fsnl ?class_label)
Mar 27 13:13:33 insight-terms java[2512289]:
org.apache.jena.sparql.expr.ExprException: REGEX: Pattern is not a
string: " \\(häiriö\\)"@fi
Mar 27 13:13:33 insight-terms java[2512289]: #011at
org.apache.jena.sparql.expr.E_Regex.makeRegexEngine(E_Regex.java:120)
~[fuseki-server.jar:4.6.1]
