<h3>Entries from March 2017.</h3>
+ <div class="entry">
+ <div class="title">
+ <a href="http://people.skolelinux.org/pere/blog/Free_software_archive_system_Nikita_now_able_to_store_documents.html">Free software archive system Nikita now able to store documents</a>
+ </div>
+ <div class="date">
+ 19th March 2017
+ </div>
+ <div class="body">
+ <p>The <a href="https://github.com/hiOA-ABI/nikita-noark5-core">Nikita
+Noark 5 core project</a> is implementing the Norwegian standard for
+keeping an electronic archive of government documents.
+<a href="http://www.arkivverket.no/arkivverket/Offentlig-forvaltning/Noark/Noark-5/English-version">The
+Noark 5 standard</a> document the requirement for data systems used by
+the archives in the Norwegian government, and the Noark 5 web interface
+specification document a REST web service for storing, searching and
+retrieving documents and metadata in such archive. I've been involved
+in the project since a few weeks before Christmas, when the Norwegian
+Unix User Group
+<a href="https://www.nuug.no/news/NOARK5_kjerne_som_fri_programvare_f_r_epostliste_hos_NUUG.shtml">announced
+it supported the project</a>. I believe this is an important project,
+and hope it can make it possible for the government archives in the
+future to use free software to keep the archives we citizens depend
+on. But as I do not hold such archive myself, personally my first use
+case is to store and analyse public mail journal metadata published
+from the government. I find it useful to have a clear use case in
+mind when developing, to make sure the system scratches one of my
+itches.</p>
+
+<p>If you would like to help make sure there is a free software
+alternatives for the archives, please join our IRC channel
+(<a href="irc://irc.freenode.net/%23nikita">#nikita on
+irc.freenode.net</a>) and
+<a href="https://lists.nuug.no/mailman/listinfo/nikita-noark">the
+project mailing list</a>.</p>
+
+<p>When I got involved, the web service could store metadata about
+documents. But a few weeks ago, a new milestone was reached when it
+became possible to store full text documents too. Yesterday, I
+completed an implementation of a command line tool
+<tt>archive-pdf</tt> to upload a PDF file to the archive using this
+API. The tool is very simple at the moment, and find existing
+<a href="https://en.wikipedia.org/wiki/Fonds">fonds</a>, series and
+files while asking the user to select which one to use if more than
+one exist. Once a file is identified, the PDF is associated with the
+file and uploaded, using the title extracted from the PDF itself. The
+process is fairly similar to visiting the archive, opening a cabinet,
+locating a file and storing a piece of paper in the archive. Here is
+a test run directly after populating the database with test data using
+our API tester:</p>
+
+<p><blockquote><pre>
+~/src//noark5-tester$ ./archive-pdf mangelmelding/mangler.pdf
+using arkiv: Title of the test fonds created 2017-03-18T23:49:32.103446
+using arkivdel: Title of the test series created 2017-03-18T23:49:32.103446
+
+ 0 - Title of the test case file created 2017-03-18T23:49:32.103446
+ 1 - Title of the test file created 2017-03-18T23:49:32.103446
+Select which mappe you want (or search term): 0
+Uploading mangelmelding/mangler.pdf
+ PDF title: Mangler i spesifikasjonsdokumentet for NOARK 5 Tjenestegrensesnitt
+ File 2017/1: Title of the test case file created 2017-03-18T23:49:32.103446
+~/src//noark5-tester$
+</pre></blockquote></p>
+
+<p>You can see here how the fonds (arkiv) and serie (arkivdel) only had
+one option, while the user need to choose which file (mappe) to use
+among the two created by the API tester. The <tt>archive-pdf</tt>
+tool can be found in the git repository for the API tester.</p>
+
+<p>In the project, I have been mostly working on
+<a href="https://github.com/petterreinholdtsen/noark5-tester">the API
+tester</a> so far, while getting to know the code base. The API
+tester currently use
+<a href="https://en.wikipedia.org/wiki/HATEOAS">the HATEOAS links</a>
+to traverse the entire exposed service API and verify that the exposed
+operations and objects match the specification, as well as trying to
+create objects holding metadata and uploading a simple XML file to
+store. The tester has proved very useful for finding flaws in our
+implementation, as well as flaws in the reference site and the
+specification.</p>
+
+<p>The test document I uploaded is a summary of all the specification
+defects we have collected so far while implementing the web service.
+There are several unclear and conflicting parts of the specification,
+and we have
+<a href="https://github.com/petterreinholdtsen/noark5-tester/tree/master/mangelmelding">started
+writing down</a> the questions we get from implementing it. We use a
+format inspired by how <a href="http://www.opengroup.org/austin/">The
+Austin Group</a> collect defect reports for the POSIX standard with
+<a href="http://www.opengroup.org/austin/mantis.html">their
+instructions for the MANTIS defect tracker system</a>, in lack of an official way to structure defect reports for Noark 5 (our first submitted defect report was a <a href="https://github.com/petterreinholdtsen/noark5-tester/blob/master/mangelmelding/sendt/2017-03-15-mangel-prosess.md">request for a procedure for submitting defect reports</a> :).
+
+<p>The Nikita project is implemented using Java and Spring, and is
+fairly easy to get up and running using Docker containers for those
+that want to test the current code base. The API tester is
+implemented in Python.</p>
+
+ </div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>, <a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn</a>, <a href="http://people.skolelinux.org/pere/blog/tags/standard">standard</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
+ <div class="entry">
+ <div class="title">
+ <a href="http://people.skolelinux.org/pere/blog/Detecting_NFS_hangs_on_Linux_without_hanging_yourself___.html">Detecting NFS hangs on Linux without hanging yourself...</a>
+ </div>
+ <div class="date">
+ 9th March 2017
+ </div>
+ <div class="body">
+ <p>Over the years, administrating thousand of NFS mounting linux
+computers at the time, I often needed a way to detect if the machine
+was experiencing NFS hang. If you try to use <tt>df</tt> or look at a
+file or directory affected by the hang, the process (and possibly the
+shell) will hang too. So you want to be able to detect this without
+risking the detection process getting stuck too. It has not been
+obvious how to do this. When the hang has lasted a while, it is
+possible to find messages like these in dmesg:</p>
+
+<p><blockquote>
+nfs: server nfsserver not responding, still trying
+<br>nfs: server nfsserver OK
+</blockquote></p>
+
+<p>It is hard to know if the hang is still going on, and it is hard to
+be sure looking in dmesg is going to work. If there are lots of other
+messages in dmesg the lines might have rotated out of site before they
+are noticed.</p>
+
+<p>While reading through the nfs client implementation in linux kernel
+code, I came across some statistics that seem to give a way to detect
+it. The om_timeouts sunrpc value in the kernel will increase every
+time the above log entry is inserted into dmesg. And after digging a
+bit further, I discovered that this value show up in
+/proc/self/mountstats on Linux.</p>
+
+<p>The mountstats content seem to be shared between files using the
+same file system context, so it is enough to check one of the
+mountstats files to get the state of the mount point for the machine.
+I assume this will not show lazy umounted NFS points, nor NFS mount
+points in a different process context (ie with a different filesystem
+view), but that does not worry me.</p>
+
+<p>The content for a NFS mount point look similar to this:</p>
+
+<p><blockquote><pre>
+[...]
+device /dev/mapper/Debian-var mounted on /var with fstype ext3
+device nfsserver:/mnt/nfsserver/home0 mounted on /mnt/nfsserver/home0 with fstype nfs statvers=1.1
+ opts: rw,vers=3,rsize=65536,wsize=65536,namlen=255,acregmin=3,acregmax=60,acdirmin=30,acdirmax=60,soft,nolock,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=129.240.3.145,mountvers=3,mountport=4048,mountproto=udp,local_lock=all
+ age: 7863311
+ caps: caps=0x3fe7,wtmult=4096,dtsize=8192,bsize=0,namlen=255
+ sec: flavor=1,pseudoflavor=1
+ events: 61063112 732346265 1028140 35486205 16220064 8162542 761447191 71714012 37189 3891185 45561809 110486139 4850138 420353 15449177 296502 52736725 13523379 0 52182 9016896 1231 0 0 0 0 0
+ bytes: 166253035039 219519120027 0 0 40783504807 185466229638 11677877 45561809
+ RPC iostats version: 1.0 p/v: 100003/3 (nfs)
+ xprt: tcp 925 1 6810 0 0 111505412 111480497 109 2672418560317 0 248 53869103 22481820
+ per-op statistics
+ NULL: 0 0 0 0 0 0 0 0
+ GETATTR: 61063106 61063108 0 9621383060 6839064400 453650 77291321 78926132
+ SETATTR: 463469 463470 0 92005440 66739536 63787 603235 687943
+ LOOKUP: 17021657 17021657 0 3354097764 4013442928 57216 35125459 35566511
+ ACCESS: 14281703 14290009 5 2318400592 1713803640 1709282 4865144 7130140
+ READLINK: 125 125 0 20472 18620 0 1112 1118
+ READ: 4214236 4214237 0 715608524 41328653212 89884 22622768 22806693
+ WRITE: 8479010 8494376 22 187695798568 1356087148 178264904 51506907 231671771
+ CREATE: 171708 171708 0 38084748 46702272 873 1041833 1050398
+ MKDIR: 3680 3680 0 773980 993920 26 23990 24245
+ SYMLINK: 903 903 0 233428 245488 6 5865 5917
+ MKNOD: 80 80 0 20148 21760 0 299 304
+ REMOVE: 429921 429921 0 79796004 61908192 3313 2710416 2741636
+ RMDIR: 3367 3367 0 645112 484848 22 5782 6002
+ RENAME: 466201 466201 0 130026184 121212260 7075 5935207 5961288
+ LINK: 289155 289155 0 72775556 67083960 2199 2565060 2585579
+ READDIR: 2933237 2933237 0 516506204 13973833412 10385 3190199 3297917
+ READDIRPLUS: 1652839 1652839 0 298640972 6895997744 84735 14307895 14448937
+ FSSTAT: 6144 6144 0 1010516 1032192 51 9654 10022
+ FSINFO: 2 2 0 232 328 0 1 1
+ PATHCONF: 1 1 0 116 140 0 0 0
+ COMMIT: 0 0 0 0 0 0 0 0
+
+device binfmt_misc mounted on /proc/sys/fs/binfmt_misc with fstype binfmt_misc
+[...]
+</pre></blockquote></p>
+
+<p>The key number to look at is the third number in the per-op list.
+It is the number of NFS timeouts experiences per file system
+operation. Here 22 write timeouts and 5 access timeouts. If these
+numbers are increasing, I believe the machine is experiencing NFS
+hang. Unfortunately the timeout value do not start to increase right
+away. The NFS operations need to time out first, and this can take a
+while. The exact timeout value depend on the setup. For example the
+defaults for TCP and UDP mount points are quite different, and the
+timeout value is affected by the soft, hard, timeo and retrans NFS
+mount options.</p>
+
+<p>The only way I have been able to get working on Debian and RedHat
+Enterprise Linux for getting the timeout count is to peek in /proc/.
+But according to
+<ahref="http://docs.oracle.com/cd/E19253-01/816-4555/netmonitor-12/index.html">Solaris
+10 System Administration Guide: Network Services</a>, the 'nfsstat -c'
+command can be used to get these timeout values. But this do not work
+on Linux, as far as I can tell. I
+<ahref="http://bugs.debian.org/857043">asked Debian about this</a>,
+but have not seen any replies yet.</p>
+
+<p>Is there a better way to figure out if a Linux NFS client is
+experiencing NFS hangs? Is there a way to detect which processes are
+affected? Is there a way to get the NFS mount going quickly once the
+network problem causing the NFS hang has been cleared? I would very
+much welcome some clues, as we regularly run into NFS hangs.</p>
+
+ </div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
<div class="entry">
<div class="title">
<a href="http://people.skolelinux.org/pere/blog/How_does_it_feel_to_be_wiretapped__when_you_should_be_doing_the_wiretapping___.html">How does it feel to be wiretapped, when you should be doing the wiretapping...</a>
important difference, and it make me sad that the journalists are
unable to grasp it.</p>
+<p><strong>Update 2017-03-13:</strong> Look like
+<a href="https://theintercept.com/2017/03/13/rand-paul-is-right-nsa-routinely-monitors-americans-communications-without-warrants/">The
+Intercept report that US Senator Rand Paul confirm what I state above</a>.</p>
+
</div>
<div class="tags">
<h2>Archive</h2>
<ul>
+<li>2018
+<ul>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/01/">January (1)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/02/">February (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/03/">March (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/04/">April (3)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/06/">June (2)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/07/">July (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/08/">August (3)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/09/">September (3)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/10/">October (4)</a></li>
+
+</ul></li>
+
<li>2017
<ul>
<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/02/">February (3)</a></li>
-<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/03/">March (3)</a></li>
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/03/">March (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/04/">April (2)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/06/">June (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/07/">July (1)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/08/">August (1)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/09/">September (3)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/10/">October (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/11/">November (3)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/12/">December (4)</a></li>
</ul></li>
<h2>Tags</h2>
<ul>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (13)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (16)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/amiga">amiga (1)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/bankid">bankid (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin (9)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin (10)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (16)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (17)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/bsa">bsa (2)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/chrpath">chrpath (2)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (147)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (163)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu (158)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/debian-handbook">debian-handbook (3)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/debian-handbook">debian-handbook (4)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/digistan">digistan (10)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/dld">dld (16)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/dld">dld (17)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/docbook">docbook (23)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/docbook">docbook (25)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/drivstoffpriser">drivstoffpriser (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (344)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (389)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (23)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (12)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (13)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/freeculture">freeculture (29)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/freeculture">freeculture (32)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/freedombox">freedombox (9)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/intervju">intervju (42)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/isenkram">isenkram (15)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/isenkram">isenkram (16)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/kart">kart (20)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/kodi">kodi (3)</a></li>
+
<li><a href="http://people.skolelinux.org/pere/blog/tags/ldap">ldap (9)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/lego">lego (4)</a></li>
+
<li><a href="http://people.skolelinux.org/pere/blog/tags/lenker">lenker (8)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/lsdvd">lsdvd (2)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/mesh network">mesh network (8)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (39)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (41)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software (9)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software (10)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk (287)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk (299)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug (187)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug (191)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn (28)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn (34)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/open311">open311 (2)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (64)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (72)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (99)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (107)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/raid">raid (1)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/raid">raid (2)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/reactos">reactos (1)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/rss">rss (1)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/ruter">ruter (5)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/ruter">ruter (6)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/scraperwiki">scraperwiki (2)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (52)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (55)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/sitesummary">sitesummary (4)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/skepsis">skepsis (5)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/standard">standard (51)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/standard">standard (56)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/stavekontroll">stavekontroll (5)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/stavekontroll">stavekontroll (6)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/stortinget">stortinget (11)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/stortinget">stortinget (12)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (48)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (55)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (2)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (4)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/usenix">usenix (2)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/valg">valg (8)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/valg">valg (9)</a></li>
+
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/verkidetfri">verkidetfri (13)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/video">video (59)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/video">video (69)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/vitenskap">vitenskap (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (40)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (41)</a></li>
</ul>
projects / homepage.git / blobdiff