Increase page and batch sizes and reduce delays
Set PAGE_SIZE to 500 and PAGE_DELAY_MS to 0, add YIELD_EVERY_N_PAGES
to yield periodically between pages. Remove the small initial connection
delay and reduce per-page logging frequency to once every 10 pages.
Increase BATCH_SIZE to 200 and lower BATCH_TIMEOUT_MS to 50. Remove
verbose ping/pong log messages.