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Many thanks,<div><br></div><div>I'll give that a go. I am however a little worried about having a safe_fixtable "active" on a table for 900 seconds so might need to be a little smarter.</div><div><br></div><div>Cheers</div><div><br></div><div>Matt<br><br><div><div id="SkyDrivePlaceholder"></div>> Date: Mon, 15 Oct 2012 14:50:34 +0200<br>> From: sverker.eriksson@ericsson.com<br>> To: mattevans123@hotmail.com<br>> CC: erlang-questions@erlang.org<br>> Subject: Re: [erlang-questions] ets:select badarg question (R15B)<br>> <br>> You need to use ets:safe_fixtable/2 to get a "sensible" result from <br>> select/match with continuation on unordered tables. Otherwise you may <br>> miss records, get double hits and (as in your case) get badarg if the <br>> table has shrunken due to deleted record causing the continuation to <br>> point out of table bounds. One could argue that '$end_of_table' would be <br>> a more suitable result than badarg for this case.<br>> <br>> I see that the documentation is not clear about this. It describes usage <br>> of safe_fixtable together with first/1 and next/2 but it does not state <br>> that it also is needed for select/match with continuation.<br>> Single call select/match does not need safe_fixtable.<br>> <br>> /Sverker, Erlang/OTP<br>> <br>> Matthew Evans wrote:<br>> > Hi<br>> > These are the options<br>> ><br>> ><br>> > ets:new(StationIdTableName,[{keypos,2},named_table,public]),<br>> > The only odd things I can think of is that during the select records are getting deleted and added. Also, the select operation is run slowly (over 900 seconds)<br>> > Again, this isn't every time I get the crash.<br>> > Matt<br>> ><br>> > <br>> >> Date: Mon, 15 Oct 2012 11:49:14 +0200<br>> >> From: sverker.eriksson@ericsson.com<br>> >> To: mattevans123@hotmail.com<br>> >> CC: erlang-questions@erlang.org<br>> >> Subject: Re: [erlang-questions] ets:select badarg question (R15B)<br>> >><br>> >> What options are you using when the table is created?<br>> >><br>> >> /Sverker, Erlang/OTP<br>> >><br>> >> Matthew Evans wrote:<br>> >> <br>> >>> Hi,<br>> >>> I'm running a select with a continuation on a public ets table with approximately 20,000 records.<br>> >>> The original call to the select is: ets:select(TableName,[{'$1',[],['$_']}],RecordsToGet), then an ets:select/1 on the continuation.<br>> >>><br>> >>><br>> >>><br>> >>><br>> >>><br>> >>><br>> >>><br>> >>><br>> >>> The process that is spawned to walk the table is sitting in a recursive loop doing a select (grabbing about 150 records each time), processing the matching records (which includes possibly deleting some of these records), then sleeping for a few seconds. It takes about 900 seconds to walk through the table. As well as records getting deleted, new records are added to the table during this time.<br>> >>> Every now and then I get an exception in the process doing the select/1:<br>> >>> Error in process <0.16218.1> on node 'xxxxx@E039D7001180' with exit value: {badarg,[{ets,select,[{'table_E0:39:D7:00:11:80',301,6,<<0 bytes>>,[{p_MacEntry....... (truncated here)<br>> >>> This is the code (all running in the same process that started the select) obviously the last ets:select is causing the crash:<br>> >>><br>> >>><br>> >>><br>> >>><br>> >>><br>> >>><br>> >>><br>> >>><br>> >>> start_aging1(AgeInterval,MaxAge,SelectData) -><br>> >>> start_aging1(AgeInterval,MaxAge,SelectData,0).<br>> >>> start_aging1(_AgeInterval,_MaxAge,'$end_of_table',RecsAged) -><br>> >>> gen_server:cast(?MODULE,{completed_aging_operation,RecsAged});<br>> >>> start_aging1(_AgeInterval,MaxAge,{Matches,'$end_of_table'},RecsAged) -><br>> >>> RecordsAgedCount = age_records(Matches,[],MaxAge*1000000,os:timestamp()),<br>> >>> gen_server:cast(?MODULE,{completed_aging_operation,RecsAged+RecordsAgedCount});<br>> >>> start_aging1(AgeInterval,MaxAge,{Matches,Continuation},RecsAged) -><br>> >>> RecordsAgedCount = age_records(Matches,[],MaxAge*1000000,os:timestamp()),<br>> >>> timer:sleep(AgeInterval),<br>> >>> start_aging1(AgeInterval,MaxAge,ets:select(Continuation),RecsAged+RecordsAgedCount).<br>> >>><br>> >>> I'm not sure what could be the cause of the select getting a bad arg.<br>> >>> Any ideas?<br>> >>> Thanks<br>> >>> Matt <br>> >>> <br>> >>> ------------------------------------------------------------------------<br>> >>><br>> >>> _______________________________________________<br>> >>> erlang-questions mailing list<br>> >>> erlang-questions@erlang.org<br>> >>> http://erlang.org/mailman/listinfo/erlang-questions<br>> >>> <br>> >>> <br>> > <br>> > <br>> <br></div></div> </div></body>
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