Buffer pool design

[eric-haibin-lin]

start with simple consumer / producer design

[eric-haibin-lin]

• Two queues per backend logger (cond var)
• force putBuffer() for every fsync
• bufferPool code for SiloR

[eric-haibin-lin]

From the Silo paper and code:

• log-buffer backpressure is not used in SiloR. SiloR’s loggers instead recirculate log buffers back to workers as soon as possible— after a write, rather than after the following epoch change and fsync.
• spinlock is used when no log buffer is available

[eric-haibin-lin]

source code

@MattPerron