Slows down renderFile in Yii2 on VPS server apache2-itk php 7.0?

Question

Yii

Installed a yii2 project on the VPS server. Pages do not always slow down (1 to 5 requests). When viewing the log, yii2 shows brakes on renderFile. I start deleting blocks one at a time, other renders and the picture remains the same, but in other renders the brakes appear.
DBMS postgres 9.5, OS ubuntu, php 7.0
percent vps Intel(R) Xeon(R) CPU E5-2630 v2 @ 2.60GHz (3 cores), 3g RAM.
What could be the problem? The system is not loaded htop does not draw any load at all on the server. I'm the only one working on it at the moment.