Something that I've wished for in Bitcoin core itself the last few days is an option to monitor the size ( in both transactions and kilobytes) of the memory pool of unconfirmed transactions. I've been seeing it get up to 3000 or so and staying there for hours during the last few days, while some miners continue to turn in tiny 60k blocks that have a few dozen transactions at most.
uh.
$ ~/bitcoin/src/bitcoin-cli getmempoolinfo
{
"size" : 320,
"bytes" : 562732
}or your friendly neighborhood debug console.
Since you weren't aware of the command, I'm guessing "seeing it" means bc.i-- take that with a huge heap of salt.