<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span style='mso-fareast-language:EN-US'>Thank you for suggestion, I will investigate mnesia_eleveldb.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>How about backups? If I have a table using an alternative backend, like LevelDB, can I still use regular mnesia:backup and mnesia:install_fallback functions to handle backups?<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>Thanks,<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>Wojtek<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US>From:</span></b><span lang=EN-US> Dan Gudmundsson <dangud@gmail.com> <br><b>Sent:</b> 20 September 2021 12:25<br><b>To:</b> Wojtek Surowka <wojteksurowka@me.com><br><b>Cc:</b> Erlang Questions <erlang-questions@erlang.org><br><b>Subject:</b> Re: Fragment not locked - again<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>I only looked briefly the last time you pointed it out, and it does look strange, <o:p></o:p></p><div><p class=MsoNormal>though I have not had time to dig deeper into it.<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>If you use fragmented tables to be able store larger tables on disk_only,<o:p></o:p></p></div><div><p class=MsoNormal>maybe you should look at <a href="https://github.com/klarna/mnesia_eleveldb">https://github.com/klarna/mnesia_eleveldb</a> or some<o:p></o:p></p></div><div><p class=MsoNormal>other backend. I have not used it myself but there are people on this list using it.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>/Dan<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Sun, Sep 19, 2021 at 5:09 PM Wojtek Surowka <<a href="mailto:wojteksurowka@me.com">wojteksurowka@me.com</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><p class=MsoNormal style='margin-bottom:12.0pt'>I have sent the same question some time ago but could not get any solution.<br>Maybe this time I will be luckier, especially that I made new observations:<br><br>I have a fragmented table in Mnesia of type disc_only_copies. There is a 2GB<br>size limit for tables of that type, and this table grows continuously with<br>new data. Because of that I have the code which periodically (weekly) checks<br>sizes of fragments and adds new fragments (usually just one) if necessary.<br>The call I use to add a new fragment is:<br><br>mnesia:change_table_frag(name, {add_frag, [node()]}).<br><br>And it works, till it does not. Right now my table is in a state when any<br>call to add a new fragment returns<br><br>{aborted,{"add_frag: Fragment not locked",12}}<br><br>All earlier change_table_frag calls were successful, but it looks like at<br>certain moment something bad happened and since then adding a new fragment<br>to the table is not possible. Every time it returns the error message. Is it<br>a bug in Mnesia? Is there anything I could do to continue adding new<br>fragments?<br><br>Thanks,<br>Wojtek<br><br><o:p></o:p></p></blockquote></div></div></body></html>