Mysql_installation

Sun, 07 Feb 2021 18:33:58 +0800

The general view of the difference between mysql and marinaDB can refer to this link:

https://blog.panoply.io/a-comparative-vmariadb-vs-mysql

And I quote some here:

MySQL: MySQL is an open-source relational database management system (RDBMS). Just like all other relational databases, MySQL uses tables, constraints, triggers, roles, stored procedures and views as the core components that you work with. A table consists of rows, and each row contains a same set of columns. MySQL uses primary keys to uniquely identify each row (a.k.a record) in a table, and foreign keys to assure the referential integrity between two related tables.

Linux_name_space

Fri, 01 Jan 2021 14:52:01 +0800

Linux NameSpace

Docker denpends on Linux NameSpace, Thus this is a brief explaination on linux name space.

We can use unshare command to manipulate/playaround with linux name spaces.

How to check what kind of linux namespace is supported

We can use “man unshare” to check what kind of linux namespace is supported. There are 8 types of name spaces:

 mount namespace
 Mounting and unmounting filesystems will not affect the rest of the system (CLONE_NEWNS flag), except for filesystems which are explicitly marked as shared (with mount --make-shared; see /proc/self/mountinfo or
 findmnt -o+PROPAGATION for the shared flags).

 unshare automatically sets propagation to private in the new mount namespace to make sure that the new namespace is really unshared. This feature is possible to disable by option --propagation unchanged. Note
 that private is the kernel default.

 UTS namespace
 Setting hostname or domainname will not affect the rest of the system. (CLONE_NEWUTS flag)

 IPC namespace
 The process will have an independent namespace for System V message queues, semaphore sets and shared memory segments. (CLONE_NEWIPC flag)

 network namespace
 The process will have independent IPv4 and IPv6 stacks, IP routing tables, firewall rules, the /proc/net and /sys/class/net directory trees, sockets, etc. (CLONE_NEWNET flag)

 pid namespace
 Children will have a distinct set of PID to process mappings from their parent. (CLONE_NEWPID flag)

 user namespace
 The process will have a distinct set of UIDs, GIDs and capabilities. (CLONE_NEWUSER flag)

 See clone(2) for the exact semantics of the flags.

Mount（mnt） isolate mounting space
Process ID (pid) isolate process ID.
Network (net) isolate network , port ID, etc
Interprocess Communication (ipc) isolate System V IPC & POSIX message queues
UTS Namespace(uts) Isolate hostname and domain name
User Namespace (user) isolate user group and users.

Additionally, Linux 4.6 and 5.6 introduced cgroups and time two types. in total it’s 8.

squid_setup

Thu, 18 Jun 2020 23:15:45 +0800

1. yum -y update

2. yum install openssl

3. yum install squid

4. vim /etc/squid/squid.conf

5. tail -f /var/log/squid/access.log

6. systemctl start squid

7. systemctl status squid

8. ss -nlp | grep squid | grep 3128

dns_nameservers 8.8.8.8 8.8.4.4

Operating System on Council of Elrond

Mysql_installation

Linux_name_space

Linux NameSpace

How to check what kind of linux namespace is supported

squid_setup