Bloom

Bloom is a server, which contains Bloom filter probabilistic data structure in memory, provides access to it via HTTP and ensures data persistence on disk by mean of atomic consistent snapshots.

---

❤️ ❤️ ❤️

You can say thanks to the author by donations to these wallets:

• ETH: 0xB71250010e8beC90C5f9ddF408251eBA9dD7320e
• BTC:
  • Legacy: 1N89PRvG1CSsUk9sxKwBwudN6TjTPQ1N8a
  • Segwit: bc1qc0hcyxc000qf0ketv4r44ld7dlgmmu73rtlntw

---

Building

Consider also Prebuilt Docker image, binaries on Releases page to use prebuilt ones and installation from Snap Store.

Debian/Ubuntu

Run these commands in sources directory:

sudo apt-get install build-essential libevent-dev
make

RHEL/OEL/CentOS

Run these commands in sources directory:

sudo yum install gcc libevent2-devel make
make

Run make static instead of make to build static binary.

Mac OS X

Assuming you are using Homebrew

brew install libevent
make

Static build for Mac OS X is not available now.

FreeBSD

According to siege benchmarks, GCC compiler gains better performance for this application. If you want to use BSD cc, you may change CC variable in Makefile. Application can be built using both of them.

pkg install gcc libevent2
make

Run make static instead of make to build static binary.

Solaris

You have to build libevent2 before:

sudo pkg install gcc
wget https://github.com/libevent/libevent/releases/download/release-2.0.22-stable/libevent-2.0.22-stable.tar.gz
tar xf libevent-2.0.22-stable.tar.gz
cd libevent-2.0.22-stable
./configure
make
sudo make install

You may also need to add /usr/local/lib to library search path:

sudo crle
# Settings output here. Check output and add /usr/local/lib at the end, delimiting it by colon
sudo crle -l /lib:/usr/lib:/usr/local/lib

After that, run build of Bloom from its directory:

make

Static build for Solaris is not available now.

Installing

Prebuilt Docker image

Run:

docker volume bloom
docker run -dit \
    -v bloom:/var/lib/bloom \
    -p 8889:8889 \
    --restart unless-stopped \
    --name bloom \
    yarmak/bloom \
    /var/lib/bloom/bloom.dat

Help:

docker run -it \
    yarmak/bloom \
    -h

From source built before

make install

to install dynamic binary.

From Snap Store

sudo snap install bloom

Usage

Running daemon

bloom <filename_for_snapshot> or ./bloom.static <filename_for_snapshot> if you prefer statically linked version.

Command line options:

$ bloom -h
Usage: bloom [options] SNAPSHOT_FILE

Options:

-H BIND_ADDRESS		HTTP interface bind address. Default: 0.0.0.0

-P BIND_PORT		HTTP interface bind port. Default: 8889

-h			Print this help message

-m M			Number of bits in bloom filter. Default: 2^33

-k K			Number of hash functions. Default: 10

-t SECONDS		Dump bloom filter snapshot to file every SECONDS
			seconds. You can set this value to 0 if you wish
			to disable this feature - snapshots are taken on USR1
			signal and at exit in any case.

Default settings is suitable for containing 500,000,000 elements with false positive probability 0.1%. See also Utilities for parameters calculator.

Querying

Test whether an element is a member of a set:

$ curl http://127.0.0.1:8889/check?e=sdfdsafdsafsadf
MISSING

Add an element to set:

$ curl http://127.0.0.1:8889/add?e=sdfdsafdsafsadf
ADDED

Check then add at once:

$ curl http://127.0.0.1:8889/checkthenadd?e=aaaaaabbb
MISSING
$ curl http://127.0.0.1:8889/checkthenadd?e=aaaaaabbb
PRESENT

Saving set

Server saves data to snapshot file in following cases:

• Server exit (received SIGTERM or SIGINT)
• Timer event. By default server dumps snapshot to disk every 5 minutes. See also help for option -t.
• On SIGUSR1 signal. This way you may control dump process on your own by sending signal to daemon.

Snapshot dumping process does not blocks serving request and uses copy-on-write method, so dumped data is always consistent.

Utilities

• utils/collision_meter.py - Check structure occupancy by measuring false positive probability on completely random requests.
• utils/bf_calc.py - Calculate parameters of bloom filter for given number of elements and false positives probability.