SimpleSSHD for Android

通过google play安装到手机,默认端口为2222,app手机启动后,需要点击启动按钮开启服务。app上会显示手机ip。

然后通过电脑ssh客户端连接,如 ssh -p 2222,连接建立后会在app上显示随机分配的密码,再客户端输入后可以成功登陆了。可以在ssh文件目录下添加 authorized_keys文件,这样就不用每次输入了。

手机sd卡的目录为 /sdcard/,连接的普通用户是有读写访问权限的。可以使用rsync把手机相册的问题件同步到电脑上。rsync -e ‘ssh -p 2222’ -rtvpl .



Algorithm: Practical Set Reconciliation

《Practical Set Reconciliation》
Yaron Minsky Cornell University
Ari Trachtenberg Boston University

def set_reconcile(src_seq, dst_seq):
    "Return required operations to mutate src_seq into dst_seq"
    src_set= set(src_seq) # no-op if already of type set
    dst_set= set(dst_seq) # ditto

    for item in src_set - dst_set:
        yield 'delete', item

    for item in dst_set - src_set:
        yield 'create', item

for i in set_reconcile([1,2,3,4], [2,3,4,5]):
    print i

$ python 
('delete', 1)
('create', 5)

Meet Casper

Casper was my colleague in Red Hat, we haven’t met each other for about 4 years. We knew same friends in Opensource communities before he join in Red Hat. He is working for Aliyun on system software area.

They want to cooperate with Universities, share their cool technology, provide guide and job position (intern or regular) for the students.

They investigated and used machine-learning in system software, one success usecase is key-value search, it’s quicker than hash table, but only for read most situation, that’s popular in their production environment.


– cpu sse4.2 flag check
– init the uptime timer
– app template/config/options
– query_processor
– get storage_proxy
– get migration_manager
– http_context ctx (create)
– prometheus
– app.run_deprecated()
– parse args
– tcp_syncookies check
– seastar::async()
– dma read cfg
– apply logging settings
– verify rlimit(openfile)
– mem_per_shard 2 ** 32 ~= 1G
– check partitioner, Murmur3Partitioner is recommended
– cfg: assign setup parameters
– start prometheus API server
– set broadcast/broadcast_rpc
– client encryption
– create trace/snitch
– dns/api_address
– start API server(ctx.http_server)
– init storage service
– init per-shard core
– start engine
– init data dir
– init commitlog dir
– * init system keyspace
– * start gossip by init_ms_fd_gossiper()
– * start storage proxy
– start migration manager
– start query processor
– init batchlog manager
– init metrics?
– mini setup (sys ks)
– legacy schema migrate
– loading sstables
– setup sys ks
– start commitlog
– set storage/gossip/snitch/storage_proxy/load_sstable server to ctx
– init migration manager rpc verbs
– init storage proxy rpc verbs
– * start streaming service
– starting msg service
– start storage service
– start load broadcaster
– start cf/cache hit rate
– start native transport ( start (thrift) rpc)
– * set_server_done
– at_exit():
– repair_shutdown
– drain_on_shutdown
– compaction_manager stop

Key components
– storage proxy
– migration manager
– partitioner
– prometheus API server
– engine
– query processor
– streaming service
– thrift rpc
– compaction manager

[转发] 招聘 | 40K – 60K 招资深架构师、资深软件工程师

2017-05-11 CSDN企业招聘


涛思数据(TAOS Data)专注实时大数据的高效采集、存储、查询和分析。其自主开发的核心引擎写入数据的速度比普通数据库快五倍以上,查询速度快十倍以上。技术能广泛运用于物联网和金融行业,能大幅提升大数据系统的性能和容量,并降低运营成本。


Continue reading “[转发] 招聘 | 40K – 60K 招资深架构师、资深软件工程师”

First ScyllaDB Summit

Scylla is the world’s fastest column-store database: the functionality of Apache Cassandra with the speed of a light key/value store.

Raw speed isn’t just a nice benchmark or a low cloud bill. Scylla’s order of magnitude improvement in performance opens a wide range of possibilities.  Instead of designing a complex data model to achieve adequate performance, use a straightforward data model, eliminate complexity, and finish your NoSQL project in less time with fewer bugs.

Performance improvements enable not just reduction in hardware resources, but also a reduction in architecture, debugging, and devops labor. Scylla combines the  simple and familiar Cassandra architecture with new power to build a data model that fits the application, not tweak the model to fit the server.

Drop in replacement solution


Come to Scylla Summit for talks on performance tuning, user success stories, data modeling, upcoming features, and more.

One event brings together the whole Scylla community – from core developers to DevOps professionals, to client developers, and NoSQL architects. We are still accepting proposals for talks—see the Call for Papers section for details.


Share your experience with ScyllaDB! Tell us how Scylla is used in your organization. Topics of interest include:

  • Best practices
  • Scylla use cases
  • Integration with analytics and IoT workloads
  • Scylla projects of all kinds – from small clusters to Internet scale

Please submit your abstract to The deadline for abstracts is August 1, 2016.

Abstract should be no longer than 500 words. Please include a targeted audience level (novice, intermediate, expert), your name, affiliation, email address, a short speaker bio, and a phone number we can use to contact you.

More info: