jpuyy的网志

Author: jpuyy

  • cassandra 操作记录

    查看状态

    bin/nodetool status

    查看所有的 keyspaces

    DESCRIBE KEYSPACES

    查看网络状态

    bin/nodetool netstats

    查看 gossipinfo

    bin/nodetool gossipinfo

    修改 replication factor 之后进行 repair

    bin/nodetool repair

    踢除一个活的节点

    bin/nodetool decommision

    导出一个 keyspace 的结构

    cqlsh -e "DESC KEYSPACE test" > db_schema_test.cql;

    导出所有 keyspace 的结构

    cqlsh -e "DESC SCHEMA" > db_schema.cql

    导出表至 csv 文件

    COPY table_name ( column , ... )
TO  'file_name' | STDOUT 
WITH option = 'value' AND ...

    当需要维护一个结点时

    cd /opt/platform/cassandra/
    bin/nodetool drain
    # stop
    pgrep -u ops -f cassandra | xargs kill -9

    # start
    nohup ./bin/cassandra &

    变更后 Check
    /opt/platform/cassandra/bin/nodetool status
    关注

    Status – U (up) or D (down)
    Indicates whether the node is functioning or not.

    State – N (normal), L (leaving), J (joining), M (moving)
    The state of the node in relation to the cluster.

  • less 查找忽略大小写

    平时使用

    cat config.json | less

    如果有大小区分的时候搜索时不太方便

    现在只使用小写搜索

    cat config.json | less -i

  • mysqldump 加 where 条件

    导出表，时间大于 2017-05-17

    mysqldump -u root -p dw tracking --where 'stm > 2017-05-17' > dw.tracking.2017-05-17.sql

  • 《荒野求生》金句

    荒野虽险，身体+头脑依然能够生存，在社会上行走，也是行走在荒野

    Survival can be summed up in three words – never give up. That’s the heart of it really. Just keep trying.
    The line between life or death is determined by what we are willing to do.
    If you risk nothing you gain nothing
    If you can find a path with no obstacles, it probably doesn’t lead anywhere.
    There is little faith involved in setting out on a journey where the destination is certain and every step in between has been mapped in detail. Bravery, trust, is about leaving camp in the dark, when we do not know the route ahead and cannot be certain we will ever return.
    When you find yourself thinking about someone or something in the same old negative way, just stop yourself. Think. Check. Change. Refresh. Job done. Smile. Move on. Do this enough times and you will change. For the better; for the stronger.
    And if you give your heart to a goal, it will repay you. It’s the law of the universe.
    Stick to the fight when you’re hardest hit, It’s when things seem worst that you must not quit.
    There is no education like adversity.
    Tentative is no power.

  • git diff 换行

    git --no-pager diff

    or

    git diff --color | less -R

    显示改动过的文件

    git diff --staged --name-only  | cat

    比较 feature 分支和 master 分支具体一个文件的变动

    git diff feature/sftp-server master -- .gitlab-ci.yml

    https://stackoverflow.com/questions/4099742/how-to-compare-files-from-two-different-branches

  • 更改 mysql 慢查询时间阈值

    默认是 10s ，改为 200ms 

    mysql> show global variables like 'long_query_time%';
+-----------------+-----------+
| Variable_name   | Value     |
+-----------------+-----------+
| long_query_time | 10.000000 |
+-----------------+-----------+
1 row in set (0.01 sec)

mysql> set global long_query_time=0.2;
Query OK, 0 rows affected (0.01 sec)

mysql> show global variables like 'long_query_time%';
+-----------------+----------+
| Variable_name   | Value    |
+-----------------+----------+
| long_query_time | 0.200000 |
+-----------------+----------+
1 row in set (0.00 sec)