also passes. Finally, TiDB has a theoretical dependence on CLOCK_MONOTONIC_RAW for safety, but we have not yet observed anomalies due to clock skew, possibly due to tooling limitations. PingCAP has published are some wall-clock dependencies in TiDB. Placement Driver, for instance, allocates timestamps based on local wall-clocks, but ensures monotonicity through Raft plus a leader lease. Clock skew between PD shouldn’t result in prolonged un- availability: PD will allocate timestamps in the future if its own clock falls behind what’s committed to Raft. To improve throughput, PD nodes reserve a batch of timestamps

system testing ● Errors can happen anywhere, any time ● Hardware ○ disk error ○ network error ○ CPU ○ clock ● Software ○ file system ○ network & protocol ○ library ● We need to simulate everything What is

database system that requires clock synchronization between nodes to guarantee linear consistency of transactions in the ACID model. At present, the common solution to clock synchronization is to use the following command to see whether your system is configured to use chronyd instead of ntpd to perform clock synchronization with NTP: sudo systemctl status chronyd.service chronyd.service - NTP client/server caused by machine failure during scheduling – TSO allocation is no longer affected by the system clock going backwards – Support the Region merge feature to reduce the overhead brought by metadata •

database system that requires clock synchronization between nodes to guarantee linear consistency of transactions in the ACID model. At present, the common solution to clock synchronization is to use the following command to see whether your system is configured to use chronyd instead of ntpd to perform clock synchronization with NTP: sudo systemctl status chronyd.service chronyd.service - NTP client/server caused by machine failure during scheduling – TSO allocation is no longer affected by the system clock going backwards – Support the Region merge feature to reduce the overhead brought by metadata •

database system that requires clock synchronization between nodes to guarantee linear consistency of transactions in the ACID model. At present, the common solution to clock synchronization is to use the following command to see whether your system is configured to use chronyd instead of ntpd to perform clock synchronization with NTP: sudo systemctl status chronyd.service chronyd.service - NTP client/server caused by machine failure during scheduling – TSO allocation is no longer affected by the system clock going backwards – Support the Region merge feature to reduce the overhead brought by metadata •

database system that requires clock synchronization between nodes to guarantee linear consistency of transactions in the ACID model. At present, the common solution to clock synchronization is to use the following command to see whether your system is configured to use chronyd instead of ntpd to perform clock synchronization with NTP: sudo systemctl status chronyd.service chronyd.service - NTP client/server continuity. | You need to customize the application. External ID generators strongly rely on the clock accuracy and might introduce failures. | | TiDB will act as the primary and write-intensive database

database system that requires clock synchronization between nodes to guarantee linear consistency of transactions in the ACID model. At present, the common solution to clock synchronization is to use the following command to see whether your system is configured to use chronyd instead of ntpd to perform clock synchronization with NTP: sudo systemctl status chronyd.service chronyd.service - NTP client/server occurs, and verify that the NTP clock synchronization service is enabled between the PD components before the failure. If it is not enabled, you need to adjust the local clock to a future time to prevent the

database system that requires clock synchronization between nodes to guarantee linear consistency of transactions in the ACID model. At present, the common solution to clock synchronization is to use the following command to see whether your system is configured to use chronyd instead of ntpd to perform clock synchronization with NTP: sudo systemctl status chronyd.service chronyd.service - NTP client/server continuity. | You need to customize the application. External ID generators strongly rely on the clock accuracy and might introduce failures. | | TiDB will act as the primary and write-intensive database

database system that requires clock synchronization between nodes to guarantee linear consistency of transactions in the ACID model. At present, the common solution to clock synchronization is to use the following command to see whether your system is configured to use chronyd instead of ntpd to perform clock synchronization with NTP: sudo systemctl status chronyd.service chronyd.service - NTP client/server continuity. | You need to customize the application. External ID generators strongly rely on the clock accuracy and might introduce failures. | | TiDB will act as the primary and write-intensive database

database system that requires clock synchronization between nodes to guarantee linear consistency of transactions in the ACID model. At present, the common solution to clock synchronization is to use the following command to see whether your system is configured to use chronyd instead of ntpd to perform clock synchronization with NTP: sudo systemctl status chronyd.service chronyd.service - NTP client/server continuity. | You need to customize the application. External ID generators strongly rely on the clock accuracy and might introduce failures. | | TiDB will act as the primary and write-intensive database