Version: 7.0.0

UWAL ​

Introduction ​

This chapter describes how to install and use the Unified Write-Ahead Log (UWAL) feature of the openGauss database. This feature combines the database and a Huawei-developed UWAL component to improve the performance of active/standby transaction submission as well as streaming replication and transmission, accelerating the Write-Ahead Log (WAL) processing efficiency.

Preparations ​

Obtaining the Installation Package ​

Obtain the UWAL installation package from the openGauss community.

Environment Requirements ​

Item

Configuration

Description

Network adapter

The model is subject to the actual environment, for example, Mellanox CX4/CX5 NICs.

It must support RDMA and Ethernet, and the RDMA protocol must be enabled. For details, refer to the RDMA Network Guide.

Switch

-

  • To enable the RDMA protocol, configure a lossless network.
  • You do not need to configure a lossless network for the TCP protocol.

Server

-

  • To enable the RDMA protocol, configure a lossless network.
  • You do not need to configure a lossless network for the TCP protocol.

OS

  • Arm
    • openEuler 22.03 LTS
    • openEuler 20.03 LTS
  • x86
    • openEuler 22.03 LTS
    • openEuler 20.03 LTS
    • CentOS 7.6 x86

-

Software

MLNX_OFED_LINUX-5.8-1.1.2.1

To enable the RDMA protocol, install the RDMA NIC driver.

  • GCC 7.3
  • GCC 10.3

-

  • OCK_UWAL_23.0.0_centos-7.6-x86_64_gcc10.tar.gz
  • OCK_UWAL_23.0.0_centos-7.6-x86_64_gcc7.tar.gz
  • OCK_UWAL_23.0.0_openeuler_20.03-aarch64_gcc10.tar.gz
  • OCK_UWAL_23.0.0_openeuler_20.03-aarch64_gcc7.tar.gz
  • OCK_UWAL_23.0.0_openeuler_20.03-x86_64_gcc10.tar.gz
  • OCK_UWAL_23.0.0_openeuler_20.03-x86_64_gcc7.tar.gz
  • OCK_UWAL_23.0.0_openeuler_22.03-aarch64_gcc10.tar.gz
  • OCK_UWAL_23.0.0_openeuler_22.03-aarch64_gcc7.tar.gz
  • OCK_UWAL_23.0.0_openeuler_22.03-x86_64_gcc10.tar.gz
  • OCK_UWAL_23.0.0_openeuler_22.03-x86_64_gcc7.tar.gz

UWAL installation package. In the package names, openeuler_22.03/centos-7.6 indicates the OS, aarch64/x86_64 indicates the server architecture, and gcc10/gcc7 indicates the GCC version on which the package depends. Select a UWAL installation package as required.

Installation and Uninstallation ​

One-Click Deployment of the UWAL Feature ​

UWAL allows one-click deployment through a simple deployment script.

  • Prerequisites

    • openGauss has been deployed.
    • Obtain the UWAL installation package corresponding to the OS and CPU architecture in use, for example, OCK_UWAL_23.0.0_openeuler_22.03-aarch64_gcc10.tar.gz.
    • The following directories exist on both the active and standby nodes:
      • ${GAUSSHOME}/lib
      • UWAL file storage path (value of uwal_devices_path)
      • UWAL log file storage path (value of uwal_log_path)

  • Procedure

    NOTE

    Unless otherwise specified, perform the following operations only on the active node.

    1. Upload the installation package to the node and run the following command in the directory where the installation package is stored to grant permissions to the openGauss database user:

      chown omm:dbgrp OCK_UWAL_23.0.0_openeuler_22.03-aarch64_gcc10.tar.gz

      NOTE

      • omm: database administrator
      • dbgrp: user group of the database administrator

    2. Switch to the openGauss database administrator and decompress the installation package.

      su - omm
tar -xzvf OCK_UWAL_23.0.0_openeuler_22.03-aarch64_gcc10.tar.gz

      The following files are extracted.

      File

      Description

      OCK_UWAL_23.0.0_openeuler_aarch64.tar.gz

      Source package

      OCK_UWAL_23.0.0_openeuler_aarch64.tar.gz.txt

      Signature file

      OCK_UWAL_23.0.0_openeuler_aarch64.tar.gz.cms

      Description file

    3. Decompress the source package.

      tar -xzvf OCK_UWAL_23.0.0_openeuler_22.03_aarch64_gcc10.tar.gz

      The following files are extracted.

      File

      Description

      lib

      SO file

      scripts

      Installation script

      include

      UWAL header file

      bin

      Signature verification file

      NOTE

      To decompress the source package again, delete the preceding files before performing decompression operations.

    4. Use the verification binary file in the bin directory to verify the software package signature.

      ./bin/verification OCK_UWAL_23.0.0_openeuler_22.03_aarch64_gcc10.tar.gz OCK_UWAL_23.0.0_openeuler_22.03_aarch64_gcc10.tar.gz.cms OCK_UWAL_23.0.0_openeuler_22.03_aarch64_gcc10.tar.gz.txt

      NOTE

      The verification binary file requires three parameters in sequence: source package, signature file, and description file.

      • If the verification is successful, the console displays the following information:

        Starting to verify OCK_UWAL_23.0.0_openeuler_22.03_aarch64_gcc10.tar.gz...
Verify the source file passed.
Verify the sha file passed.

      • If the verification fails, the console displays the following information:

        Starting to verify OCK_UWAL_23.0.0_openeuler_22.03_aarch64_gcc10.tar.gz...
...
Verify the source file failed.

        Or

        Starting to verify OCK_UWAL_23.0.0_openeuler_22.03_aarch64_gcc10.tar.gz...
...
Verify the sha file failed.

        NOTE

        If the verification fails, the installation package has been tampered with. You are advised to obtain the installation package again and verify it again.

    5. After the installation package is verified, go to the scripts directory.

      cd scripts

    6. Run the script to complete the UWAL deployment.

      sh ock_uwal_install.sh -H '192.168.4.164 192.168.4.165 192.168.4.166' -U omm -D /home/omm/lib

      NOTE

      • -H: IP addresses in the cluster. Example: '192.168.4.164 192.168.4.165 192.168.4.166'
      • -U: user name of the database administrator. Example: omm
      • -D: path to the ${GAUSSHOME}/lib library. Example: /home/omm/lib
      • -h: help information.

    7. (Optional) Kill the om_monitor process.

      gs_om -t killmonitor

    8. Run the following command to load environment variables:

      source ~/.bashrc

      NOTICE

      This step is also required on the standby node.

    9. (Optional) The UWAL component depends on the HCOM component for RPC communication. Configure the following environment variables as required.

      export HCOM_FILE_PATH_PREFIX="/home/uds/socket/file"
export HCOM_OPENSSL_PATH="/home/openssl"
export HCOM_TRACE_LEVEL=0
export HCOM_QP_TRAFFIC_CLASS=106
export HCOM_SHM_EXCHANGE_FD_QUEUE_SIZE=10
export HCOM_CONNECTION_RETRY_TIMES=5
export HCOM_CONNECTION_RETRY_INTERVAL_SEC=2

      The following table describes the parameters.

      Parameter

      Type

      Description

      Value Range

      Default Value

      HCOM_FILE_PATH_PREFIX

      Character string

      Prefix of the path to files generated by HCOM. The prefix ensures that the files are generated and deleted only in the current path (the path must exist).

      -

      -

      HCOM_OPENSSL_PATH

      Character string

      Path to the OpenSSL library on which HCOM depends. This path is the directory of libssl.so and libcrypt.so.

      -

      -

      HCOM_TRACE_LEVEL

      Integer

      HCOM trace level. The options are as follows:

      • 0: Disables tracing.
      • 1: Enables high-priority tracing.
      • 2: Enables medium-priority tracing.
      • 3: Enables low-priority tracing.

      0–3

      0

      HCOM_QP_TRAFFIC_CLASS

      Integer

      Set the priority of the traffic_class field of the RDMA protocol in HCOM.

      0–255

      106

      HCOM_SHM_EXCHANGE_FD_QUEUE_SIZE

      Integer

      Size of the FDS internal queue sent by HCOM.

      10–256

      10

      HCOM_CONNECTION_RETRY_TIMES

      Integer

      Number of HCOM connection setup retries.

      0–10

      5

      HCOM_CONNECTION_RETRY_INTERVAL_SEC

      Integer

      Interval between each HCOM connection setup retry, in seconds.

      0–60

      20

Enabling the UWAL Feature ​

To enable the UWAL feature, modify the configuration file and restart the database for the modification to take effect.

NOTICE

Once the UWAL feature is enabled, it cannot be disabled.

  • Prerequisites

    • The openGauss version that contains the UWAL feature has been installed on the active and standby nodes.
    • The UWAL feature has been deployed in one-click mode.

  • Procedure

    1. Log in to the management node as the database administrator.
    2. Modify the postgresql.conf file of the database.

      1. Open the postgresql.conf file.

        vim postgresql.conf

      2. Press i to enter the insert mode and add the following parameters to the end of the file. One active node and one standby node are used as an example. Set the parameters based on the actual environment. For details about the parameters, see Table 1.

        replconninfo1='localhost=10.10.10.201 localport=5432 remotehost=10.10.10.207 remoteport=5432 remotenodeid=2 remoteuwalhost=10.10.10.207 remoteuwalport=9991'
enable_uwal = on
uwal_config = '{"uwal_nodeid": 0, "uwal_ip": "10.10.10.201", "uwal_port": 9991, "uwal_protocol": "tcp", "cpu_bind_switch": "true", "cpu_bind_start": 1, "cpu_bind_num": 3}'
uwal_disk_size = 8589934592
uwal_devices_path = '/home/Data/uwal/'
uwal_log_path = '/home/Data/opengauss_master/uwal_log'
uwal_rpc_compression_switch = true
uwal_rpc_flowcontrol_switch = true
uwal_rpc_flowcontrol_value = 128
uwal_async_append_switch = false
application_name = 'node201'

        NOTE

        • If there are one active node and two standby nodes, add the replconninfo2 parameter to the next line of the replconninfo1 parameter. For example:
replconninfo2='localhost=10.10.10.201 localport=5432 remotehost=10.10.10.208 remoteport=5432 remotenodeid=2 remoteuwalhost=10.10.10.208 remoteuwalport=9991'
  • If there are one active node and N standby nodes, add parameters replconninfo2 to replconninfoN in sequence.
        **Table  1**  UWAL configuration parameters

        <a name="table135651186916"></a>
        <table><thead align="left"><tr id="row25651989917"><th class="cellrowborder" valign="top" width="23.126556486302924%" id="mcps1.2.5.1.1"><p id="p656518814920"><a name="p656518814920"></a><a name="p656518814920"></a>Parameter</p>
        </th>
        <th class="cellrowborder" valign="top" width="8.071088974417027%" id="mcps1.2.5.1.2"><p id="p1588918155523"><a name="p1588918155523"></a><a name="p1588918155523"></a>Type</p>
        </th>
        <th class="cellrowborder" valign="top" width="44.60040751641386%" id="mcps1.2.5.1.3"><p id="p156538994"><a name="p156538994"></a><a name="p156538994"></a>Description</p>
        </th>
        <th class="cellrowborder" valign="top" width="24.2019470228662%" id="mcps1.2.5.1.4"><p id="p756568792"><a name="p756568792"></a><a name="p756568792"></a>Value Range</p>
        </th>
        <th class="cellrowborder" valign="top" width="20%" id="mcps1.2.5.1.5"><p id="p756568799"><a name="p756568799"></a><a name="p756568799"></a>Default Value</p>
        </th>
        </tr>
        </thead>
        <tbody><tr id="row1344716210013"><td class="cellrowborder" valign="top" width="23.126556486302924%" headers="mcps1.2.5.1.1 "><p id="p15447202403"><a name="p15447202403"></a><a name="p15447202403"></a>replconninfo{N}</p>
        </td>
        <td class="cellrowborder" valign="top" width="8.071088974417027%" headers="mcps1.2.5.1.2 "><p id="p4447122006"><a name="p4447122006"></a><a name="p4447122006"></a>Character string</p>
        </td>
        <td class="cellrowborder" valign="top" width="44.60040751641386%" headers="mcps1.2.5.1.3 "><p id="p12291125152313"><a name="p12291125152313"></a><a name="p12291125152313"></a>Configures the IP address and port number of the remote UWAL node. Add <strong id="b672042117595"><a name="b672042117595"></a><a name="b672042117595"></a>remotenodeid</strong> (<strong id="b3886172635911"><a name="b3886172635911"></a><a name="b3886172635911"></a>uwal_nodeid</strong> of the remote node), <strong id="b12336173695913"><a name="b12336173695913"></a><a name="b12336173695913"></a>remoteuwalhost</strong> (<strong id="b121021840185914"><a name="b121021840185914"></a><a name="b121021840185914"></a>uwal_ip</strong> of the remote node), and <strong id="b172327115014"><a name="b172327115014"></a><a name="b172327115014"></a>remoteuwalport</strong> (<strong id="b2092294606"><a name="b2092294606"></a><a name="b2092294606"></a>uwal_port</strong> of the remote node) to the end of the original parameters. <span class="parmvalue" id="parmvalue10543195803112"><a name="parmvalue10543195803112"></a><a name="parmvalue10543195803112"></a><b>N</b></span> specifies the information about the <em id="i13971812771"><a name="i13971812771"></a><a name="i13971812771"></a>N</em>th node to be listened on and authenticated by the current node.</p>
        </td>
        <td class="cellrowborder" valign="top" width="24.2019470228662%" headers="mcps1.2.5.1.4 "><p id="p11263735204712"><a name="p11263735204712"></a><a name="p11263735204712"></a>Character string. An empty string indicates that no information about the <em id="i13952538174210"><a name="i13952538174210"></a><a name="i13952538174210"></a>N</em>th node is configured.</p>
        </td>
        <td class="cellrowborder" valign="top" width="8%" headers="mcps1.2.5.1.5 "><p id="p4447122007"><a name="p4447122007"></a><a name="p4447122007"></a>Empty string</p>
        </td>
        </tr>
        <tr id="row14252637115317"><td class="cellrowborder" valign="top" width="23.126556486302924%" headers="mcps1.2.5.1.1 "><p id="p8252203735311"><a name="p8252203735311"></a><a name="p8252203735311"></a>enable_uwal</p>
        </td>
        <td class="cellrowborder" valign="top" width="8.071088974417027%" headers="mcps1.2.5.1.2 "><p id="p152521637135313"><a name="p152521637135313"></a><a name="p152521637135313"></a>Boolean</p>
        </td>
        <td class="cellrowborder" valign="top" width="44.60040751641386%" headers="mcps1.2.5.1.3 "><p id="p625212379535"><a name="p625212379535"></a><a name="p625212379535"></a>Specifies whether to enable the UWAL feature.</p>
        </td>
        <td class="cellrowborder" valign="top" width="24.2019470228662%" headers="mcps1.2.5.1.4 "><a name="ul1730195610532"></a><a name="ul1730195610532"></a><ul id="ul1730195610532"><li><strong id="b1452384910287"><a name="b1452384910287"></a><a name="b1452384910287"></a>on</strong>: enable.</li><li><strong id="b6504818122920"><a name="b6504818122920"></a><a name="b6504818122920"></a>off</strong>: disable.</li></ul>
        </td>
        <td class="cellrowborder" valign="top" width="8%" headers="mcps1.2.5.1.5 "><p id="p4447122007"><a name="p4447122007"></a><a name="p4447122007"></a>off</p>
        </td>
        </tr>
        <tr id="row459675018428"><td class="cellrowborder" valign="top" width="23.126556486302924%" headers="mcps1.2.5.1.1 "><p id="p859675013425"><a name="p859675013425"></a><a name="p859675013425"></a>uwal_config</p>
        </td>
        <td class="cellrowborder" valign="top" width="8.071088974417027%" headers="mcps1.2.5.1.2 "><p id="p2596195011427"><a name="p2596195011427"></a><a name="p2596195011427"></a>Character string</p>
        </td>
        <td class="cellrowborder" valign="top" width="44.60040751641386%" headers="mcps1.2.5.1.3 "><p id="p1473010295313"><a name="p1473010295313"></a><a name="p1473010295313"></a>UWAL configuration.</p>
        </td>
        <td class="cellrowborder" valign="top" width="24.2019470228662%" headers="mcps1.2.5.1.4 "><p id="p059665015426"><a name="p059665015426"></a><a name="p059665015426"></a>Character string of the JSON type.</p>
        </td>
        <td class="cellrowborder" valign="top" width="8%" headers="mcps1.2.5.1.5 "><p id="p4447122007"><a name="p4447122007"></a><a name="p4447122007"></a>Empty string</p>
        </td>
        </tr>
        <tr id="row4407698390"><td class="cellrowborder" valign="top" width="23.126556486302924%" headers="mcps1.2.5.1.1 "><p id="p1840715973919"><a name="p1840715973919"></a><a name="p1840715973919"></a>uwal_disk_size</p>
        </td>
        <td class="cellrowborder" valign="top" width="8.071088974417027%" headers="mcps1.2.5.1.2 "><p id="p1140717915395"><a name="p1140717915395"></a><a name="p1140717915395"></a>Integer</p>
        </td>
        <td class="cellrowborder" valign="top" width="44.60040751641386%" headers="mcps1.2.5.1.3 "><p id="p17407792391"><a name="p17407792391"></a><a name="p17407792391"></a>Disk size occupied by UWAL. The value cannot exceed the total disk size. Unit: byte.</p>
        </td>
        <td class="cellrowborder" valign="top" width="24.2019470228662%" headers="mcps1.2.5.1.4 "><p id="p16829854115014"><a name="p16829854115014"></a><a name="p16829854115014"></a>Minimum value: <strong id="b76064162412"><a name="b76064162412"></a><a name="b76064162412"></a>8589934592</strong></p>
        <p id="p17120172118219"><a name="p17120172118219"></a><a name="p17120172118219"></a>Maximum value: <strong id="b4234201910417"><a name="b4234201910417"></a><a name="b4234201910417"></a>4398046511104</strong></p>
        </td>
        <td class="cellrowborder" valign="top" width="8%" headers="mcps1.2.5.1.5 "><p id="p4447122007"><a name="p4447122007"></a><a name="p4447122007"></a>8589934592</p>
        </td>
        </tr>
        <tr id="row124911412194316"><td class="cellrowborder" valign="top" width="23.126556486302924%" headers="mcps1.2.5.1.1 "><p id="p1849211210431"><a name="p1849211210431"></a><a name="p1849211210431"></a>uwal_devices_path</p>
        </td>
        <td class="cellrowborder" valign="top" width="8.071088974417027%" headers="mcps1.2.5.1.2 "><p id="p949214126432"><a name="p949214126432"></a><a name="p949214126432"></a>Character string</p>
        </td>
        <td class="cellrowborder" valign="top" width="44.60040751641386%" headers="mcps1.2.5.1.3 "><p id="p649211210432"><a name="p649211210432"></a><a name="p649211210432"></a>Path for storing UWAL files. The path must be an existing path. It is the input parameter name when the UwalInit() function is invoked.</p>
        </td>
        <td class="cellrowborder" valign="top" width="24.2019470228662%" headers="mcps1.2.5.1.4 "><p id="p13444115913211"><a name="p13444115913211"></a><a name="p13444115913211"></a>Character string of the file storage path.</p>
        </td>
        <td class="cellrowborder" valign="top" width="8%" headers="mcps1.2.5.1.5 "><p id="p4447122007"><a name="p4447122007"></a><a name="p4447122007"></a>Empty string</p>
        </td>
        </tr>
        <tr id="row138231819439"><td class="cellrowborder" valign="top" width="23.126556486302924%" headers="mcps1.2.5.1.1 "><p id="p1138281811439"><a name="p1138281811439"></a><a name="p1138281811439"></a>uwal_log_path</p>
        </td>
        <td class="cellrowborder" valign="top" width="8.071088974417027%" headers="mcps1.2.5.1.2 "><p id="p11382161815431"><a name="p11382161815431"></a><a name="p11382161815431"></a>Character string</p>
        </td>
        <td class="cellrowborder" valign="top" width="44.60040751641386%" headers="mcps1.2.5.1.3 "><p id="p1832318524495"><a name="p1832318524495"></a><a name="p1832318524495"></a>Path for storing UWAL log files. The path must be an existing path.</p>
        </td>
        <td class="cellrowborder" valign="top" width="20%" headers="mcps1.2.5.1.5 "><p id="p19301132112336"><a name="p19301132112336"></a><a name="p19301132112336"></a>Character string of the file storage path.</p>
        </td>
        <td class="cellrowborder" valign="top" width="24.2019470228662%" headers="mcps1.2.5.1.4 "><p id="p19301132112335"><a name="p19301132112335"></a><a name="p19301132112335"></a>Empty string</p>
        </td>
        </tr>
        <tr id="row15325134455119"><td class="cellrowborder" valign="top" width="23.126556486302924%" headers="mcps1.2.5.1.1 "><p id="p143269444516"><a name="p143269444516"></a><a name="p143269444516"></a>uwal_rpc_compression_switch</p>
        </td>
        <td class="cellrowborder" valign="top" width="8.071088974417027%" headers="mcps1.2.5.1.2 "><p id="p9792504515"><a name="p9792504515"></a><a name="p9792504515"></a>Boolean</p>
        </td>
        <td class="cellrowborder" valign="top" width="44.60040751641386%" headers="mcps1.2.5.1.3 "><p id="p17326344185111"><a name="p17326344185111"></a><a name="p17326344185111"></a>Specifies whether to enable compressed transfer.</p>
        </td>
        <td class="cellrowborder" valign="top" width="24.2019470228662%" headers="mcps1.2.5.1.4 "><a name="ul723414185211"></a><a name="ul723414185211"></a><ul id="ul723414185211"><li><strong id="b46211635163012"><a name="b46211635163012"></a><a name="b46211635163012"></a>true</strong>: enable.</li><li><strong id="b1526114493016"><a name="b1526114493016"></a><a name="b1526114493016"></a>false</strong>: disable.</li></ul>
        </td>
        <td class="cellrowborder" valign="top" width="8%" headers="mcps1.2.5.1.5 "><p id="p4447122007"><a name="p4447122007"></a><a name="p4447122007"></a>false</p>
        </td>
        </tr>
        <tr id="row20803334125218"><td class="cellrowborder" valign="top" width="23.126556486302924%" headers="mcps1.2.5.1.1 "><p id="p680363414522"><a name="p680363414522"></a><a name="p680363414522"></a>uwal_rpc_flowcontrol_switch</p>
        </td>
        <td class="cellrowborder" valign="top" width="8.071088974417027%" headers="mcps1.2.5.1.2 "><p id="p26042047125212"><a name="p26042047125212"></a><a name="p26042047125212"></a>Boolean</p>
        </td>
        <td class="cellrowborder" valign="top" width="44.60040751641386%" headers="mcps1.2.5.1.3 "><p id="p1560715215815"><a name="p1560715215815"></a><a name="p1560715215815"></a>Specifies whether to enable flow control for the asynchronous standby database. This parameter is set on the active database.</p>
        </td>
        <td class="cellrowborder" valign="top" width="24.2019470228662%" headers="mcps1.2.5.1.4 "><a name="ul175600166531"></a><a name="ul175600166531"></a><ul id="ul175600166531"><li><strong id="b3132859183014"><a name="b3132859183014"></a><a name="b3132859183014"></a>on</strong>: enable.</li><li><strong id="b024329143120"><a name="b024329143120"></a><a name="b024329143120"></a>off</strong>: disable.</li></ul>
        </td>
        <td class="cellrowborder" valign="top" width="8%" headers="mcps1.2.5.1.5 "><p id="p4447122007"><a name="p4447122007"></a><a name="p4447122007"></a>off</p>
        </td>
        </tr>
        <tr id="row1861817512539"><td class="cellrowborder" valign="top" width="23.126556486302924%" headers="mcps1.2.5.1.1 "><p id="p106188514539"><a name="p106188514539"></a><a name="p106188514539"></a>uwal_rpc_flowcontrol_value</p>
        </td>
        <td class="cellrowborder" valign="top" width="8.071088974417027%" headers="mcps1.2.5.1.2 "><p id="p3618115110538"><a name="p3618115110538"></a><a name="p3618115110538"></a>Integer</p>
        </td>
        <td class="cellrowborder" valign="top" width="44.60040751641386%" headers="mcps1.2.5.1.3 "><p id="p176184512531"><a name="p176184512531"></a><a name="p176184512531"></a>Flow control threshold of the asynchronous standby database. Unit: MB.</p>
        </td>
        <td class="cellrowborder" valign="top" width="24.2019470228662%" headers="mcps1.2.5.1.4 "><p id="p637754013113"><a name="p637754013113"></a><a name="p637754013113"></a>8–2048</p>
        </td>
        <td class="cellrowborder" valign="top" width="8%" headers="mcps1.2.5.1.5 "><p id="p4447122007"><a name="p4447122007"></a><a name="p4447122007"></a>128</p>
        </td>
        </tr>
        <tr id="row10727151734917"><td class="cellrowborder" valign="top" width="23.126556486302924%" headers="mcps1.2.5.1.1 "><p id="p177273171495"><a name="p177273171495"></a><a name="p177273171495"></a>uwal_async_append_switch</p>
        </td>
        <td class="cellrowborder" valign="top" width="8.071088974417027%" headers="mcps1.2.5.1.2 "><p id="p16727181734910"><a name="p16727181734910"></a><a name="p16727181734910"></a>Boolean</p>
        </td>
        <td class="cellrowborder" valign="top" width="44.60040751641386%" headers="mcps1.2.5.1.3 "><p id="p197271417124919"><a name="p197271417124919"></a><a name="p197271417124919"></a>Specifies whether UWAL uses synchronous write or asynchronous write.</p>
        </td>
        <td class="cellrowborder" valign="top" width="24.2019470228662%" headers="mcps1.2.5.1.4 "><a name="ul3411546175514"></a><a name="ul3411546175514"></a><ul id="ul3411546175514"><li><strong id="b23191546183114"><a name="b23191546183114"></a><a name="b23191546183114"></a>true</strong>: Asynchronous write is used.</li><li><strong id="b1279241123217"><a name="b1279241123217"></a><a name="b1279241123217"></a>false</strong>: Synchronous write is used.</li></ul>
        </td>
        <td class="cellrowborder" valign="top" width="8%" headers="mcps1.2.5.1.5 "><p id="p4447122007"><a name="p4447122007"></a><a name="p4447122007"></a>false</p>
        </td>
        </tr>
        <tr id="row152985345311"><td class="cellrowborder" valign="top" width="23.126556486302924%" headers="mcps1.2.5.1.1 "><p id="p92987341734"><a name="p92987341734"></a><a name="p92987341734"></a>application_name</p>
        </td>
        <td class="cellrowborder" valign="top" width="8.071088974417027%" headers="mcps1.2.5.1.2 "><p id="p17299143412311"><a name="p17299143412311"></a><a name="p17299143412311"></a>Character string</p>
        </td>
        <td class="cellrowborder" valign="top" width="44.60040751641386%" headers="mcps1.2.5.1.3 "><p id="p1529919348319"><a name="p1529919348319"></a><a name="p1529919348319"></a>Specifies the client name used in the current connection request.</p>
        </td>
        <td class="cellrowborder" valign="top" width="24.2019470228662%" headers="mcps1.2.5.1.4 "><p id="p1529911344310"><a name="p1529911344310"></a><a name="p1529911344310"></a>Any character string.</p>
        </td>
        <td class="cellrowborder" valign="top" width="8%" headers="mcps1.2.5.1.5 "><p id="p4447122007"><a name="p4447122007"></a><a name="p4447122007"></a>Empty string</p>
        </td>
        </tr>
        </tbody>
        </table>

        **Table  2**  uwal\_config parameters

        <a name="table1040322664419"></a>
        <table><thead align="left"><tr id="row04034268441"><th class="cellrowborder" valign="top" width="19.966082532504238%" id="mcps1.2.5.1.1"><p id="p111461143194516"><a name="p111461143194516"></a><a name="p111461143194516"></a>Parameter</p>
        </th>
        <th class="cellrowborder" valign="top" width="11.430186546071225%" id="mcps1.2.5.1.2"><p id="p10146124311459"><a name="p10146124311459"></a><a name="p10146124311459"></a>Type</p>
        </th>
        <th class="cellrowborder" valign="top" width="37.79536461277557%" id="mcps1.2.5.1.3"><p id="p81461543204519"><a name="p81461543204519"></a><a name="p81461543204519"></a>Description</p>
        </th>
        <th class="cellrowborder" valign="top" width="30.808366308648953%" id="mcps1.2.5.1.4"><p id="p4146124313457"><a name="p4146124313457"></a><a name="p4146124313457"></a>Value Range</p>
        </th>
        <th class="cellrowborder" valign="top" width="20%" id="mcps1.2.5.1.5"><p id="p4146124313458"><a name="p4146124313458"></a><a name="p4146124313458"></a>Default Value</p>
        </th>
        </tr>
        </thead>
        <tbody><tr id="row1840492611441"><td class="cellrowborder" valign="top" width="19.966082532504238%" headers="mcps1.2.5.1.1 "><p id="p159511917154511"><a name="p159511917154511"></a><a name="p159511917154511"></a>uwal_nodeid</p>
        </td>
        <td class="cellrowborder" valign="top" width="11.430186546071225%" headers="mcps1.2.5.1.2 "><p id="p18951517184518"><a name="p18951517184518"></a><a name="p18951517184518"></a>Integer</p>
        </td>
        <td class="cellrowborder" valign="top" width="37.79536461277557%" headers="mcps1.2.5.1.3 "><p id="p095114178458"><a name="p095114178458"></a><a name="p095114178458"></a>ID of the current UWAL node.</p>
        </td>
        <td class="cellrowborder" valign="top" width="30.808366308648953%" headers="mcps1.2.5.1.4 "><p id="p595111754512"><a name="p595111754512"></a><a name="p595111754512"></a>0–7</p>
        </td>
        <td class="cellrowborder" valign="top" width="20%" headers="mcps1.2.5.1.5 "><p id="p595111754513"><a name="p595111754513"></a><a name="p595111754513"></a>None</p>
        </td>
        </tr>
        <tr id="row4404142620442"><td class="cellrowborder" valign="top" width="19.966082532504238%" headers="mcps1.2.5.1.1 "><p id="p69511017174510"><a name="p69511017174510"></a><a name="p69511017174510"></a>uwal_ip</p>
        </td>
        <td class="cellrowborder" valign="top" width="11.430186546071225%" headers="mcps1.2.5.1.2 "><p id="p19511617154512"><a name="p19511617154512"></a><a name="p19511617154512"></a>Character string</p>
        </td>
        <td class="cellrowborder" valign="top" width="37.79536461277557%" headers="mcps1.2.5.1.3 "><p id="p1795101715458"><a name="p1795101715458"></a><a name="p1795101715458"></a>UWAL listening address, which is the input parameter name when the UwalInit() function is invoked.</p>
        </td>
        <td class="cellrowborder" valign="top" width="30.808366308648953%" headers="mcps1.2.5.1.4 "><p id="p795111794512"><a name="p795111794512"></a><a name="p795111794512"></a>IPv4</p>
        </td>
        <td class="cellrowborder" valign="top" width="20%" headers="mcps1.2.5.1.5 "><p id="p595111754513"><a name="p595111754513"></a><a name="p595111754513"></a>Empty string</p>
        </td>
        </tr>
        <tr id="row44041726104418"><td class="cellrowborder" valign="top" width="19.966082532504238%" headers="mcps1.2.5.1.1 "><p id="p14951161784518"><a name="p14951161784518"></a><a name="p14951161784518"></a>uwal_port</p>
        </td>
        <td class="cellrowborder" valign="top" width="11.430186546071225%" headers="mcps1.2.5.1.2 "><p id="p20951317134520"><a name="p20951317134520"></a><a name="p20951317134520"></a>Integer</p>
        </td>
        <td class="cellrowborder" valign="top" width="37.79536461277557%" headers="mcps1.2.5.1.3 "><p id="p895117171458"><a name="p895117171458"></a><a name="p895117171458"></a>UWAL listening port, which is the input parameter name when the UwalInit() function is invoked.</p>
        </td>
        <td class="cellrowborder" valign="top" width="30.808366308648953%" headers="mcps1.2.5.1.4 "><p id="p119516171453"><a name="p119516171453"></a><a name="p119516171453"></a>9000–65535</p>
        </td>
        <td class="cellrowborder" valign="top" width="20%" headers="mcps1.2.5.1.5 "><p id="p595111754513"><a name="p595111754513"></a><a name="p595111754513"></a>None</p>
        </td>
        </tr>
        <tr id="row14404182611442"><td class="cellrowborder" valign="top" width="19.966082532504238%" headers="mcps1.2.5.1.1 "><p id="p8951161719452"><a name="p8951161719452"></a><a name="p8951161719452"></a>uwal_protocol</p>
        </td>
        <td class="cellrowborder" valign="top" width="11.430186546071225%" headers="mcps1.2.5.1.2 "><p id="p149511317134514"><a name="p149511317134514"></a><a name="p149511317134514"></a>Character string</p>
        </td>
        <td class="cellrowborder" valign="top" width="37.79536461277557%" headers="mcps1.2.5.1.3 "><p id="p695113171452"><a name="p695113171452"></a><a name="p695113171452"></a>(Optional) Connection protocol of the current node, which is the input parameter name when the UwalInit() function is invoked.</p>
        </td>
        <td class="cellrowborder" valign="top" width="30.808366308648953%" headers="mcps1.2.5.1.4 "><a name="ul795119174457"></a><a name="ul795119174457"></a><ul id="ul795119174457"><li>tcp</li><li>rdma</li></ul>
        </td>
        <td class="cellrowborder" valign="top" width="20%" headers="mcps1.2.5.1.5 "><p id="p595111754513"><a name="p595111754513"></a><a name="p595111754513"></a>tcp</p>
        </td>
        </tr>
        <tr id="row7404142611449"><td class="cellrowborder" valign="top" width="19.966082532504238%" headers="mcps1.2.5.1.1 "><p id="p59524178454"><a name="p59524178454"></a><a name="p59524178454"></a>cpu_bind_switch</p>
        </td>
        <td class="cellrowborder" valign="top" width="11.430186546071225%" headers="mcps1.2.5.1.2 "><p id="p139521917124511"><a name="p139521917124511"></a><a name="p139521917124511"></a>Character string</p>
        </td>
        <td class="cellrowborder" valign="top" width="37.79536461277557%" headers="mcps1.2.5.1.3 "><p id="p995281715454"><a name="p995281715454"></a><a name="p995281715454"></a>(Optional) Specifies whether to enable core binding for UWAL core threads.</p>
        </td>
        <td class="cellrowborder" valign="top" width="30.808366308648953%" headers="mcps1.2.5.1.4 "><a name="ul495219179451"></a><a name="ul495219179451"></a><ul id="ul495219179451"><li><strong id="b333733943320"><a name="b333733943320"></a><a name="b333733943320"></a>true</strong>: enable.</li><li><strong id="b1915194816338"><a name="b1915194816338"></a><a name="b1915194816338"></a>false</strong>: disable.</li></ul>
        </td>
        <td class="cellrowborder" valign="top" width="20%" headers="mcps1.2.5.1.5 "><p id="p595111754513"><a name="p595111754513"></a><a name="p595111754513"></a>false</p>
        </td>
        </tr>
        <tr id="row19404926124410"><td class="cellrowborder" valign="top" width="19.966082532504238%" headers="mcps1.2.5.1.1 "><p id="p1695231715458"><a name="p1695231715458"></a><a name="p1695231715458"></a>cpu_bind_start</p>
        </td>
        <td class="cellrowborder" valign="top" width="11.430186546071225%" headers="mcps1.2.5.1.2 "><p id="p1952317184512"><a name="p1952317184512"></a><a name="p1952317184512"></a>Integer</p>
        </td>
        <td class="cellrowborder" valign="top" width="37.79536461277557%" headers="mcps1.2.5.1.3 "><p id="p199521217134513"><a name="p199521217134513"></a><a name="p199521217134513"></a>(Optional) Start CPU core used for UWAL core binding.</p>
        </td>
        <td class="cellrowborder" valign="top" width="30.808366308648953%" headers="mcps1.2.5.1.4 "><p id="p49528172459"><a name="p49528172459"></a><a name="p49528172459"></a>0–1024</p>
        </td>
        <td class="cellrowborder" valign="top" width="20%" headers="mcps1.2.5.1.5 "><p id="p595111754513"><a name="p595111754513"></a><a name="p595111754513"></a>1</p>
        </td>
        </tr>
        <tr id="row204058264440"><td class="cellrowborder" valign="top" width="19.966082532504238%" headers="mcps1.2.5.1.1 "><p id="p4952717194510"><a name="p4952717194510"></a><a name="p4952717194510"></a>cpu_bind_num</p>
        </td>
        <td class="cellrowborder" valign="top" width="11.430186546071225%" headers="mcps1.2.5.1.2 "><p id="p1095211714511"><a name="p1095211714511"></a><a name="p1095211714511"></a>Integer</p>
        </td>
        <td class="cellrowborder" valign="top" width="37.79536461277557%" headers="mcps1.2.5.1.3 "><p id="p89529171458"><a name="p89529171458"></a><a name="p89529171458"></a>(Optional) Number of CPU cores bound to UWAL.</p>
        </td>
        <td class="cellrowborder" valign="top" width="30.808366308648953%" headers="mcps1.2.5.1.4 "><p id="p1795231715454"><a name="p1795231715454"></a><a name="p1795231715454"></a>2–16</p>
        </td>
        <td class="cellrowborder" valign="top" width="20%" headers="mcps1.2.5.1.5 "><p id="p595111754513"><a name="p595111754513"></a><a name="p595111754513"></a>3</p>
        </td>
        </tr>
        </tbody>
        </table>

    3. Press  **Esc**, type  **:wq!**, and press  **Enter**  to save the file and exit.

3. Restart the database to enable the UWAL feature.
    1. Stop openGauss.

        ```
        cm_ctl stop
        ```

    2. Start openGauss.

        ```
        cm_ctl start
        ```

        >[!NOTE]NOTE 
        >If the startup fails, rectify the fault based on the  **postgresql-**_YYYY-MM-DD\_HHMMSS_**.log**  file in the openGauss log directory.

4. Verify that the UWAL feature is successfully enabled.

    ```
    gsql -d postgres -p 16600 -c "show enable_uwal"
    ```

    If the following information is displayed, the feature is enabled successfully:

    ```
    enable_uwal
    -------------------
    on
    (1 row)
    ```

    >[!NOTE]NOTE 
    >- **-p 16600**:  **16600**  indicates the database port number. Change it based on the actual environment.
    >- To view UWAL log files, go to the path specified by  **uwal\_log\_path**  and run the following command:

cat uwal*.log
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