Load stat's for MYISAM vs INNODB for feed storage on the RaspberryPI

Here are some historic load stats for a raspberrypi running here, with 36 feeds being written to.

First using the INNODB storage engine:

A load of 3.5 causes an issue where the time that is recorded for data packets coming in gets messed up creating bunched up datapoints:

Switching the storage engine over the MYISAM, reduced the load to around 0.2 and the timing issue is no longer present:


To convert your raspberry pi emoncms Innodb tables to MYISAM you can run the following script on your raspberrypi which will go through each table converting them in turn:



  $mysqli = new mysqli("localhost","root","raspberry","emoncms");

  $result = $mysqli->query("SHOW tables");
  while ($row = $result->fetch_array())
  {
    echo "ALTER TABLE `".$row[0]."` ENGINE=MYISAM\n";
    $mysqli->query("ALTER TABLE `".$row[0]."` ENGINE=MYISAM");
  }

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