PHP 5.5.10 nginx 1.5.10 Centos 6.5 a xen-based 4GB VPS
My site uses encrypted paypal buttons. This encryption is done by the following code:
$openssl_cmd = "($OPENSSL smime -sign -signer $MY_CERT_FILE -inkey $MY_KEY_FILE " . "-outform der -nodetach -binary <<_EOF_\n$data\n_EOF_\n) | " . "$OPENSSL smime -encrypt -des3 -binary -outform pem $PAYPAL_CERT_FILE"; exec($openssl_cmd, $output, $error);
A couple of times now (a few days apart) the buttons have started to fail to encode. If I run "service php-fpm restart" then everything is fine again.
This is the error given:
PHP Warning: exec(): Unable to fork [(/usr/bin/openssl smime -sign -signer /var/www/my-pubcert.pem -inkey /var/www/my-prvkey.pem -outform der -nodetach -binary <datasnipped>) | /usr/bin/openssl smime -encrypt -des3 -binary -outform pem /var/www/paypal_cert.pem]
Once it happens it seems to happen constantly until I restart php-fpm.
Any ideas what route I should go down to debug/fix this?