Can't finish download of any big file

[radistmorse]

I use nextcloud 12 which I just updated from OC 8 ( -> NC9 -> NC10 -> NC11 -> NC12).

I can't finish download of any folder (as zip archive) or any large file through normal web. The files I use are on external local mounts. Previously, right after the download failed, I saw an error in logs, identical to the one described in issue #1166, but after I applied the patch owncloud/core#26939 the error disappeared. Now the download just fails silently, without any errors.

My test folder is 3.4 GB large, containing ~200 files, and my test file is a 4.8 GB large. The download fails 15-30 seconds in, which corresponds to 30-60 MBs.

Operating system:
Debian Jessie
Web server:
nginx 1.10
Database:
MySQL 5.6
PHP version:
fpm 7
Nextcloud version: (see Nextcloud admin page)
12.0

List of activated apps:
Enabled:

• admin_audit: 1.2.0
• bruteforcesettings: 1.0.2
• comments: 1.2.0
• dav: 1.3.0
• federatedfilesharing: 1.2.0
• federation: 1.2.0
• files: 1.7.2
• files_external: 1.3.0
• files_videoplayer: 1.1.0
• logreader: 2.0.0
• lookup_server_connector: 1.0.0
• nextcloud_announcements: 1.1
• notifications: 2.0.0
• oauth2: 1.0.5
• password_policy: 1.2.2
• provisioning_api: 1.2.0
• serverinfo: 1.2.0
• sharebymail: 1.2.0
• survey_client: 1.0.0
• systemtags: 1.2.0
• theming: 1.3.0
• twofactor_backupcodes: 1.1.1
• updatenotification: 1.2.0
• workflowengine: 1.2.0
  Disabled:
• activity
• encryption
• files_pdfviewer
• files_sharing
• files_texteditor
• files_trashbin
• files_versions
• firstrunwizard
• gallery
• user_external
• user_ldap

Nextcloud configuration:
{
"system": {
"instanceid": "oc06764c673f",
"passwordsalt": "REMOVED SENSITIVE VALUE",
"trusted_domains": [
"example.com",
"192.168.10.2"
],
"datadirectory": "/usr/share/nginx/html/nextcloud/data",
"dbtype": "mysql",
"version": "12.0.0.29",
"dbname": "owncloudbase",
"dbhost": "localhost",
"dbtableprefix": "oc_",
"dbuser": "REMOVED SENSITIVE VALUE",
"dbpassword": "REMOVED SENSITIVE VALUE",
"installed": true,
"forcessl": true,
"loglevel": 0,
"theme": "",
"maintenance": false,
"secret": "REMOVED SENSITIVE VALUE",
"updater.release.channel": "stable",
"memcache.local": "\OC\Memcache\APCu"
}
}
Are you using external storage, if yes which one: local and nfs4-mounted local
Are you using encryption: no
Are you using an external user-backend, if yes which one: no

Client configuration

Browser: firefox 53
Operating system: fedora 25

Logs

Web server error log

nothing unusual

Nextcloud log (data/nextcloud.log)

no errors whatsoever. that's the whole point.

Browser log

just instant "download failed". the moment ago it was downloading with the speed of several MBs, and then - fail.

[benbrummer]

https://docs.nextcloud.com/server/9/admin_manual/configuration_files/big_file_upload_configuration.html#nginx

I guess you have to disable proxy_buffering => By default, downloads will be limited to 1GB due to proxy_buffering and proxy_max_temp_file_size on the frontend.

[radistmorse]

No, still doesn't work. I set proxy_buffering off; at the server section of nginx, and now the download sometimes fails much later - at 300 MB. I still see only the "file accessed ..." messages in the log, and nothing more.

Interestingly, the 100% cpu-eating php-fpm7.0 process remain active even after the download fails, and remains there for quite some time, before disappearing (several minutes). Two consecutive failed downloads result in two 100% cpu-eating php processes.

[derkostka]

@radistmorse is your system 32 Bit or 64 Bit ?

[radistmorse]

64bit. I updated the system to debian 9, and while doing so, I accidentally mysql database, the whole thing :)

I decided to reinitialize the DB from scratch, since I mostly used NC for external mounts, and it was easier than trying to restore the base backup. And after I did that, the download started to work again. So I guess it was some weird DB-related issue because of my OC8 -> NC9 migration. Or maybe it was related to the dotdeb nginx/php7 packaging (I use the official deb9 packages now). In any case, I don't have this issue anymore.

[tflidd]

The topic is solved and the error can't be reproduced at the moment. So closing here, we can reopen if someone can reproduce this problem.

[chocholik]

Hello, I have same problem. I want to download 187 MB zip, but downloading stops after aprox. 2,5 minutes and download only around 150 MB.
I use new instalation, NC 12, 64 bit.

Thanks

[derkostka]

@chocholik plz check your configured timeouts and file limits. How "fast" is the download until it stalls ?

Also have a look here (relevant for file uploads):
https://docs.nextcloud.com/server/12/admin_manual/configuration_files/big_file_upload_configuration.html?highlight=big%20file%20upload

Please open another issue in case configuration does not help you out.

[enricotagliavini]

I've got the same problem with NC12 and it got worst when I disabled proxy buffering. Now download fails a few MB after it starts. My nginx config:

    proxy_http_version 1.1;
    proxy_buffering off;
    proxy_buffers 64 128k;
    proxy_max_temp_file_size 0;
    large_client_header_buffers 16 32k;

The Nextcloud log says only the file is accessed

{"reqId":"Wb2i@HHq51iqoykyjl9VtgAAAAc","level":1,"time":"2017-09-16T22:17:29+00:00","remoteAddr":"<client IPv6>","user":"bcd58981-989b11e2-864f984f-feeb3534","app":"admin_audit","method":"GET","url":"\/nextcloud\/remote.php\/webdav\/Shared\<edited>","message":"File accessed: \"\/Shared\/<edited>\"","userAgent":"Mozilla\/5.0 (X11; Fedora; Linux x86_64; rv:55.0) Gecko\/20100101 Firefox\/55.0","version":"12.0.2.0"}

If I keep proxy buffering enabled (same setting as shown, just commenting the line disabling buffering), download starts and goes for a while to randomly stop at some point. It's not a timeout from nginx though, this comes only after because the backend actually stalls.

This could be related to the use of HTTP2. Removing the http2 option in the listen setting of nginx mitigate the issue.... which doesn't make much sense does it?

Edit: this happens also when downloading the same file via backend web server without nextcloud in the middle, so this is not a nextcloud bug

[derkostka]

I can confirm that downloads do not work using nginx in conjunction with http2.

This persists with NC12 as well as on Master. I opened another issue for this, as the two are unrelated, so please comment here:
#6538

BTW: Apache2 is unrelated, no problems there.

[enricotagliavini]

I don't think it's a NC bug to be honest. I have the same problem downloading the same file via nginx directly (by placing it inside the document root and downloading it via URL). This is an nginx bug with http2 most likely. FYI I tried with nginx 1.10

[derkostka]

Well, good to have this feedback. I will try with nginx 1.12 and 1.13 then and review the changelogs.

Until, we should update the administrators manual and put a warning on, that only apache2 is working
https://docs.nextcloud.com/server/12/admin_manual/configuration_server/server_tuning.html?highlight=http2

[te-online]

@derkostka is this confirmed to be a nginx bug rather than a configuration problem? Is there a newer version of nginx available fixing this? I might have the same problem here, but needs more investigation...