Data Source Statistics incorrectly reports that a data source does not exist

[netniV]

I have just seen a large number of warnings from DSSTATS have appeared in my log files. When I took one of the filenames and looked for it, it was present. Therefore, this warning appears to be in error. When I used the debug plugin to verify the datasource, no issues were found.

[netniV]

The path is probably the <path_rra> which usually corresponds to /rra/

[k4y53r]

Hi,

I've also get this error after upgrade to 1.1.36, checked path and permission with no error detected on them

Update: no structured RRA used

[netniV]

I have create a patch for 1.2 that should fix this. For now, you may wish to apply the PR #1434 to your 1.1.36 system.

[MarcHagen]

After changing that line i got stuck polling processes loop infinitely and producing big log files.

11-Mar-2018 13:36:17 - CMDPHP PHP ERROR WARNING Backtrace: (/poller_boost.php: 166 dsstats_boost_bottom)(/lib/dsstats.php: 708 dsstats_get_and_store_ds_avgpeak_values)(/lib/dsstats.php: 71 dsstats_obtain_data_source_avgpeak_values)(/lib/dsstats.php: 173 dsstats_rrdtool_execute)(/lib/dsstats.php: 808 feof)(CactiErrorHandler)(/lib/functions.php: 4586 cacti_debug_backtrace)
11-Mar-2018 13:36:17 - ERROR PHP WARNING: feof() expects parameter 1 to be resource, null given in file: /usr/share/cacti/lib/dsstats.php on line: 808
11-Mar-2018 13:36:17 - CMDPHP PHP ERROR WARNING Backtrace: (/poller_boost.php: 166 dsstats_boost_bottom)(/lib/dsstats.php: 708 dsstats_get_and_store_ds_avgpeak_values)(/lib/dsstats.php: 71 dsstats_obtain_data_source_avgpeak_values)(/lib/dsstats.php: 173 dsstats_rrdtool_execute)(/lib/dsstats.php: 809 fgets)(CactiErrorHandler)(/lib/functions.php: 4586 cacti_debug_backtrace)
11-Mar-2018 13:36:17 - ERROR PHP WARNING: fgets() expects parameter 1 to be resource, null given in file: /usr/share/cacti/lib/dsstats.php on line: 809

In my case $use_proxy is false and file_exists() true.
This is due to

cacti/lib/dsstats.php

Line 55 in 5bc95d0

$use_proxy = (read_config_option('storage_location') != '' ? true:false);

uses the same wrong usage of comparing a string to an integer

Because of that the $process_pipes are not populated correctly

[netniV]

Can you open that as a separate issue so that it can be patched too.