1621
Meanwhile , virtual private server provider Linode had to reboot some of its legacy Xen servers in order to apply the fix .
 ( patch vulnerability: apply,  the fix: patch, its legacy Xen servers: vulnerable system, virtual private server provider Linode: releaser) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: phishing, data breach, ransom, discover vulnerability, patch vulnerability, Arguments type: vulnerable system, capabilities, vulnerability, number of victim, issues addressed, compromised data, damage amount, common vulnerabilities and exposures, victim, patch number, number of data, tool, discoverer, time, purpose, place, payment method, releaser, vulnerable system version, attacker, supported platform, patch, price, vulnerable system owner, trusted entity, attack pattern. 
Text: {0} 
Answer:
 ( patch vulnerability: apply,  the fix: patch, its legacy Xen servers: vulnerable system, virtual private server provider Linode: releaser) 