A grey area on the graph indicates that Quanta was unable to retrieve any data during this period or that there was no data at all.

In the case above, the graph shows the time spent in Magento or in PHP. The data is grayed out because the page was cached. Neither PHP nor Magento was called to create the page. The HTML was in memory in the cache system (Varnish type). As a result, the graph shows a greyed out area: the area where Magento or PHP data was zero.

It can also happen that the Quanta probes are non-functional for a few minutes. In order not to distort the analysis (false positives or false negatives) we remove the data. This is why it can happen that a grey bar appears on all your graphs. This is very rare.