In ExtJS v6.2.0 Do not use store.reload() method, because it leads to issue two requests to the server (https://www.sencha.com/forum/showthread.php?469984-Buffered-store-ALWAYS-send-two-requests-on-load-event-if-all-data-fetched&p=1318406#post1318406). Use store.load() instead, until this bug will be fixed.
store.reload()
store.load()
To load bufferedStore in the single request you need to adjust pageSize and leadingBufferZone.
To install Pcore, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Pcore
CPAN shell
perl -MCPAN -e shell install Pcore
For more information on module installation, please visit the detailed CPAN module installation guide.