You want to share a large read-only data set in a managed instance group ensuring low latency. What is the optimal solution?

The optimal solution utilizes a Compute Engine persistent disk attached in read-only mode to multiple instances because it provides a managed and reliable way to share a large data set among multiple instances in a managed instance group while ensuring low latency.

By using a persistent disk, multiple instances can access the same disk simultaneously without needing to deal with network latency associated with accessing data over the internet or mount points. When the persistent disk is set to read-only mode, it guarantees that the data integrity remains intact, as no instance can modify the data. This approach maintains performance and reduces complexity since the persistent disk can easily scale with the instances without requiring additional configurations for access management.

Additionally, persistent disks in Google Cloud are designed for high performance, allowing instances to access the data efficiently. This is particularly crucial when dealing with large data sets, as it facilitates faster read operations compared to other methods that may involve some form of data copying or network access.

In contrast, while other options might provide ways to access data, they may introduce latency issues and additional management overhead that is less efficient for sharing large datasets across multiple compute instances.