On the server side, the actual service of TDengine is provided by an executable `taosd` whose parameters can be configured in file `taos.cfg` to meet the requirements of different use cases. The default location of `taos.cfg` is `/etc/taos`, but can be changed by using `-c` parameter on the CLI of `taosd`. For example, the configuration file can be put under `/home/user` and used like below
```bash
taosd -c /home/user
taosd -c /home/user
```
```
另外可以使用 `-C` 显示当前服务器配置参数：
Parameter `-C` can be used on the CLI of `taosd` to show its configuration, like below:
TDengine CLI `taos` is the tool for users to interact with TDengine. It can share same configuration file as `taosd` or use a separate configuration file. When launching `taos`, parameter `-c` can be used to specify the location where its configuration file is. For example `taos -c /home/cfg` means `/home/cfg/taos.cfg` will be used. If `-c` is not used, the default location of the configuration file is `/etc/taos`. For more details please use `taos --help` to get.
**2.0.10.0 之后版本支持命令行以下参数显示当前客户端参数的配置**
From version 2.0.10.0 below commands can be used to show the configuration parameters of the client side.
TDengine uses continuous 13 ports, both TCP and TCP, from the port specified by `serverPort`. These ports need to be kept as open if firewall is enabled. Below table describes the ports used by TDengine in details.
| TCP | 6041 | REST connection between client and server | Prior to 2.4.0.0: serverPort+11; After 2.4.0.0 refer to [taosAdapter](/reference/taosadapter/) |
| Meaning | The switch for monitoring inside server. The workload of the hosts, including CPU, memory, disk, network, TTP requests, are collected and stored in a system builtin database `LOG` |
| 取值范围 | 0：关闭监控服务， 1：激活监控服务。 |
| Value Range | 0: monitoring disabled, 1: monitoring enabled 务. |
To handle the data insertion and data query from multiple timezones, Unix Timestamp is used and stored TDengie. The timestamp generated from any timezones at same time is same in Unix timestamp. To make sure the time on client side can be converted to Unix timestamp correctly, the timezone must be set properly.
在 Linux 系统中，客户端会自动读取系统设置的时区信息。用户也可以采用多种方式在配置文件设置时区。例如：
On Linux system, TDengine clients automatically obtain timezone from the host. Alternatively, the timezone can be configured explicitly in configuration file `taos.cfg` like below.
The above examples are all proper configuration for the timezone of UTC+8. On Windows system, however, `timezone Asia/Shanghai` is not supported, it must be set as `timezone UTC-8`.
时区的设置对于查询和写入 SQL 语句中非 Unix 时间戳的内容（时间戳字符串、关键词 now 的解析）产生影响。例如：
The setting for timezone impacts the strings not in Unix timestamp, keywords or functions related to date/time, for example
To avoid the problems of using time strings, Unix timestamp can be used directly. Furthermore, time strings with timezone can be used in SQL statement, for example "2013-04-12T15:52:01.123+08:00" in RFC3339 format or "2013-04-12T15:52:01.123+0800" in ISO-8601 format, they are not influenced by timezone setting when converted to Unix timestamp.
A specific type "nchar" is provied in TDengine to store non-ASCII characters such as Chinese, Japanese, Korean. The characters to be stored in nchar type are firstly encoded in UCS4-LE before sending to server side. To store non-ASCII characters correctly, the encoding format of the client side needs to be set properly.
客户端的输入的字符均采用操作系统当前默认的编码格式，在 Linux 系统上多为 UTF-8，部分中文系统编码则可能是 GB18030 或 GBK 等。在 docker 环境中默认的编码是 POSIX。在中文版 Windows 系统中，编码则是 CP936。客户端需要确保正确设置自己所使用的字符集，即客户端运行的操作系统当前编码字符集，才能保证 nchar 中的数据正确转换为 UCS4-LE 编码格式。
The characters input on the client side are encoded using the default system encoding, which is UTF-8 on Linux, or GB18030 or GBK on some systems in Chinese, POSIX in docker, CP936 on Windows in Chinese. The encoding of the operating system in use must be set correctly so that the characters in nchar type can be converted to UCS4-LE.
在 Linux 中 locale 的命名规则为: <语言>\_<地区>.<字符集编码> 如：zh_CN.UTF-8，zh 代表中文，CN 代表大陆地区，UTF-8 表示字符集。字符集编码为客户端正确解析本地字符串提供编码转换的说明。Linux 系统与 Mac OSX 系统可以通过设置 locale 来确定系统的字符编码，由于 Windows 使用的 locale 中不是 POSIX 标准的 locale 格式，因此在 Windows 下需要采用另一个配置参数 charset 来指定字符编码。在 Linux 系统中也可以使用 charset 来指定字符编码。
The locale definition standard on Linux is: <Language\>\_<Region\>.<charset\>, for example, in "zh_CN.UTF-8", "zh" means Chinese, "CN" means China mainland, "UTF-8" means charset. On Linux andMac OSX, the charset can be set by locale in the system. On Windows system another configuration parameter `charset` must be used to configure charset because the locale used on Windows is not POSIX standard. Of course, `charset` can also be used on Linux to specify the charset.
On Linux, if `charset` is not set in `taos.cfg`, when `taos` is started, the charset is obtained from system locale. If obtaining charset from system locale fails, `taos` would fail to start. So on Linux system, if system locale is set properly, it's not necessary to set `charset` in `taos.cfg`. For example:
在 Linux 系统中，locale 信息包含了字符编码信息，因此正确设置了 Linux 系统 locale 以后可以不用再单独设置 charset。例如：
```
locale zh_CN.UTF-8
```
在 Windows 系统中，无法从 locale 获取系统当前编码。如果无法从配置文件中读取字符串编码信息，taos 默认设置为字符编码为 CP936。其等效在配置文件中添加如下配置：
```
```
charset CP936
locale zh_CN.UTF-8
```
```
如果需要调整字符编码，请查阅当前操作系统使用的编码，并在配置文件中正确设置。
在 Linux 系统中，如果用户同时设置了 locale 和字符集编码 charset，并且 locale 和 charset 的不一致，后设置的值将覆盖前面设置的值。
Besides, on Linux system, if the charset contained in `locale` is not consistent with that set by `charset`, the one who comes later in the configuration file is used.
```
```title="Effective charset is GBK"
locale zh_CN.UTF-8
locale zh_CN.UTF-8
charset GBK
charset GBK
```
```
则 charset 的有效值是 GBK。
```title="Effective charset is UTF-8"
charset GBK
locale zh_CN.UTF-8
```
```
On Windows system, it's not possible to obtain charset from system locale. If it's not set in configuration file `taos.cfg`, it would be default to CP936, same as set as below in `taos.cfg`. For example
| Value Range | 0: not cached <br/> 1: the last row of each sub table is cached <br/> 2: the last non-null value of each column is cached <br/> 3: identical to both 1 and 2 are set |
| Value Range | "": lossy compression is disabled <br/> float: only for float <br/>double: only for double <br/> float \| double: for both float and double |
To prevent system resource from being exhausted by multiple concurrent streams, a random delay is applied on each stream automatically. `maxFirstStreamCompDelay` is the maximum delay time before a continuous query is started the first time. `streamCompDelayRatio` is the ratio for calculating delay time, with the size of the time window as base. `maxStreamCompDelay` is the maximum delay time. The actual delay time is a random time not bigger than `maxStreamCompDelay`. If a continuous query fails, `retryStreamComDelay` is the delay time before retrying it, also not bigger than `maxStreamCompDelay`.
The parameters described in this section are only application in versions prior to 2.4.0.0. If you are using any version from 2.4.0.0, please refer to [taosAdapter]](/reference/taosadapter/).
| Note | The generated files are named as "tscnote-xxxx.0/tscnote-xxx.1" in which "xxxx" is the pid of the client, and located at same place as client log |
| Meaning | Maximum display width of binary and nchar in taos shell. Anything beyond this limit would be hidden |
| 取值范围 | 5 - |
| Value Range | 5 - |
| 缺省值 | 30 |
| Default Value | 30 |
:::info
:::info
实际上限按以下规则计算：如果字段值的长度大于 maxBinaryDisplayWidth，则显示上限为 **字段名长度** 和 **maxBinaryDisplayWidth** 的较大者。<br/>否则，上限为 **字段名长度** 和 **字段值长度** 的较大者。<br/>可在 shell 中通过命令 set max_binary_display_width nn 动态修改此选项
If the length of value exceeds `maxBinaryDisplayWidth`, then the actual display width is max(column name, maxBinaryDisplayLength); otherwise the actual display width is max(length of column name, length of column value). This parameter can also be changed dynamically using `set max_binary_display_width <nn\>` in TDengine CLI `taos`.
| Note | The core file is generated under root directory `systemctl start taosd` is used to start, or under the working directory if `taosd` is started directly on Linux Shell. |
