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Expertise en SGBDR - Page 49

  • Restriction de mise à jour

    Cassandra versions requiring intermediate upgrades

    Be sure to read the NEWS.txt for each version back to your current version.

    Cassandra 3.0.x restrictions 

    • Upgrade from Cassandra 2.2 versions later or equal to 2.2.2 directly to Cassandra 3.0.x.
    • Upgrade from Cassandra 2.1 versions later or equal to 2.1.9 directly to Cassandra 3.0.x.
    • Direct upgrade from Cassandra 2.0 and older versions is not supported.

    Cassandra 2.2.x restrictions 

    • Upgrade from Cassandra 2.1 versions later or equal to 2.1.9 directly to Cassandra 2.2.x.
    • Direct upgrade from Cassandra 2.0 and older versions is not supported.

    Cassandra 2.1.x restrictions 

    • Upgrade from Cassandra 2.0.7 or later directly to Cassandra 2.1.
    • Cassandra 2.1 is not compatible with Cassandra 1.x SSTables. To upgrade:
      1. Upgrade the SSTables.
      2. Upgrade the nodes to Cassandra 2.0.7 or later.
      3. Start the cluster.
      4. Upgrade the SSTables again.
      5. Stop the cluster.
      6. Upgrade to Cassandra 2.1.

    Cassandra 2.0.x restrictions 

    • Upgrade to Cassandra 2.0.x directly from Cassandra 1.2.9 or later.
    • Upgrade from Cassandra earlier than 1.2.9 to Cassandra 2.0.x using a rolling restart:
      1. Upgrade the SSTables.
      2. Upgrade the entire cluster to 1.2.9
      3. Upgrade to Cassandra 2.0.
     

  • DataStax Upgrade Guide

    Procedure

    1. Familiarize yourself with the changes and features in this release:
      • General upgrade advice and Cassandra features in NEWS.txt. If you are upgrading from an earlier release, read NEWS.txt all the way back to your current version.
      • Cassandra changes in CHANGES.txt.
    2. When your Cassandra upgrade includes a major version (for example, from Cassandra 1.2 to 2.0) or a major point release (for example, from Cassandra 2.0 to 2.1), upgrade the SSTables on each node to ensure that all SSTables are on the current version. If the SSTables are already on the current version, the command returns immediately and no action is taken. 
      $ nodetool upgradesstables
    3. Run nodetool drain before shutting down the existing Cassandra service. This prevents overcounts of counter data, and also speeds up restart post-upgrade.
    4. Stop the node.
    5. Back up your configuration files.

      Depending on how you install the product, these files might get overwritten with default values during the installation. After backing up your configuration, follow the appropriate installation instructions depending on your current installation type.

    6. Install the new version of Cassandra:
    7. Configure the new product.
      Using the backups you made of your configuration files, merge any modifications you have previously made into the new configuration files for the new version. Configuration options change often, so be sure to double check the version restrictions for additional steps and changes regarding configuration.
      Ensure that the latest default values from cassandra-env.sh match your local cassandra-env.sh file.
    8. Start the node.
      An explicit compatibility check is performed on startup. If you skipped any upgrade step, startup fails. Changes from the new release are not modified, and SSTables are not upgraded to the new format. Review the error messages to correct the problem and then start the node.
    9. One each node after the upgrade is performed, run $ nodetool upgradesstables.
      Upgrading SSTables is required for Cassandra upgrades that include a major version (for example, from Cassandra 1.2 to 2.0) or a major point release (for example, from Cassandra 2.0 to 2.1).
    10. Check the logs for warnings, errors, and exceptions.
    11. Repeat these upgrade steps on each node in the cluster.

     

    Cassandra configuration files

    Configuration file Package installations Tarball installations
    cassandra.yaml /etc/cassandra/cassandra.yaml install_location/conf/cassandra.yaml
    cassandra-topology.properties /etc/cassandra/cassandra-topology.properties install_location/conf/cassandra-topology.properties
    cassandra-rackdc.properties /etc/cassandra/cassandra-rackdc.properties install_location/conf/cassandra-rackdc.properties
    cassandra-env.sh /etc/cassandra/cassandra-env.sh install_location/conf/cassandra-env.sh
    cassandra.in.sh /usr/share/cassandra/cassandra.in.sh install_location/bin/cassandra.in.sh
    logback.xml /etc/cassandra/logback.xml install_location/conf/logback.xml

    Source : https://docs.datastax.com/en/upgrade/doc/upgrade/cassandra/upgradeCassandraDetails.html

     

     

  • Sauvegardez MySQL sous Linux sans arrêter les services

    Vous connaissez probablement les deux façons régulières pour créer un instantané de votre base de données MySQL application cohérente. Nous allons ressasser :

     

     

    • Option 1. Suspendre le service MySQL
      Le service MySQL est arrêté pendant quelques secondes alors que la photo est créée puis a commencé à nouveau. La base de données (et généralement l'application sur le dessus, aussi) doivent être arrêtés. Cette disponibilité du service des impacts et de la performance (puisque tous les caches application / base de données sont effacées et doivent être reconstruites).

     

    • Option 2. Utilisez Dump en ligne
      Une décharge en ligne de chaque base de données est prise en utilisant la commande mysqldump qui copie une base de données pour le stockage accessible depuis le serveur MySQL. capacité de stockage supplémentaire et de stockage E / S sont nécessaires pour copier le fichier entier sur. Ce processus peut prendre un temps considérable.

     

    Lire la suite

  • La découverte du siècle