public Task Run(DocumentStore store)
{
var logger = store.Configuration.Logger;
var configuration = store.Configuration;
if (!configuration.RunBackgroundMigrations)
{
return(Task.CompletedTask);
}
return(Task.Factory.StartNew(() =>
{
const int batchSize = 500;
var random = new Random();
try
{
foreach (var table in configuration.Tables.Values.OfType <DocumentTable>())
{
var commands = configuration.Migrations
.SelectMany(x => x.Background(configuration), (migration, command) => (Migration: migration, Command: command))
.Concat((null, new UpdateProjectionsMigration()))
.Where(x => x.Command.Matches(configuration, table));
foreach (var migrationAndCommand in commands)
{
var(migration, command) = migrationAndCommand;
var baseDesign = configuration.TryGetDesignByTablename(table.Name)
?? throw new InvalidOperationException($"Design not found for table '{table.Name}'");
var numberOfRowsLeft = 0;
while (true)
{
var @where = command.Matches(migration?.Version);
var skip = numberOfRowsLeft > batchSize
? random.Next(0, numberOfRowsLeft)
: 0;
var rows = store
.Query(table, out var stats,
@select: "*",
@where: @where.ToString(),
window: new SkipTake(skip, batchSize),
parameters: @where.Parameters)
.ToList();
if (stats.TotalResults == 0)
{
break;
}
numberOfRowsLeft = stats.TotalResults - stats.RetrievedResults;
logger.LogInformation(
"Migrating {NumberOfDocumentsInBatch} documents from {Table}. {NumberOfPendingDocuments} documents left.",
stats.RetrievedResults, table.Name, stats.TotalResults);
using (var tx = store.BeginTransaction())
{
foreach (var row in rows)
{
var key = (string)row[DocumentTable.IdColumn];
var discriminator = ((string)row[DocumentTable.DiscriminatorColumn]).Trim();
var concreteDesign = store.Configuration.GetOrCreateDesignByDiscriminator(baseDesign, discriminator);
try
{
using (var session = new DocumentSession(store, store.Migrator, tx))
{
session.ConvertToEntityAndPutUnderManagement(concreteDesign, row);
session.SaveChanges(lastWriteWins: false, forceWriteUnchangedDocument: true);
}
}
catch (ConcurrencyException exception)
{
logger.LogInformation(exception,
"ConcurrencyException while migrating document of type '{type}' with id '{id}'. Document is migrated by the other party.",
concreteDesign.DocumentType.FullName, key);
}
catch (SqlException exception)
{
logger.LogWarning(exception,
"SqlException while migrating document of type '{type}' with id '{id}'. Will retry.",
concreteDesign.DocumentType.FullName, key);
}
catch (Exception exception)
{
logger.LogError(exception,
"Unrecoverable exception while migrating document of type '{type}' with id '{id}'. Stopping migrator for table '{table}'.",
concreteDesign.DocumentType.FullName, key, concreteDesign.Table.Name);
goto nextTable;
}
}
tx.Complete();
}
}
}
logger.LogInformation("Documents in {Table} are fully migrated to {Version}", table.Name, store.Configuration.ConfiguredVersion);
nextTable:;
}
}
catch (Exception exception)
{
logger.LogCritical(exception, _(@"
Document migration failed. Migration runner stopped.
Documents will not be migrated in background until you restart the runner."));
}
}, TaskCreationOptions.LongRunning));
}