We have developing Site for our client with Magento 2.1.5 ,in which we are facing issue on place order! , Site takes too much time to Place order approx : 2 to 3 min.
Apache Version : 2.2.15
Mysql : 5.6.36
Issue reproducible in both developer and production mode, we have varnish cache installed and configured with magento.
For sending mail we are using : php sendmail extension.
If we enable Magento ASYNCHRONOUS MAIL option then response time is little less .
Please reply with any possible reasons for this issue.
Thanks in Advance.
It could be a problem with sendmail configuration that is causing the delay. I would recommend using a code profiling tool like blackfire to identify where time is being spent. On production you can use New Relic too which can be very useful.
These kinds of delays are typically throgh misconfiguration or inaccessible third party services.