diff --git a/bin/pt-archiver b/bin/pt-archiver
index acc61b109..392b5168c 100755
--- a/bin/pt-archiver
+++ b/bin/pt-archiver
@@ -1995,7 +1995,7 @@ sub parse {
 
    my ($keys, $clustered_key) = $self->get_keys($ddl, $opts, \%is_nullable);
 
-   my ($charset) = $ddl =~ m/DEFAULT CHARSET=(\w+)/;
+   my ($charset) = $ddl =~ m/DEFAULT CHARSET\s*=\s*(\w+)/;
 
    return {
       name               => $name,
diff --git a/bin/pt-online-schema-change b/bin/pt-online-schema-change
index 1f13f9c61..3256bd300 100755
--- a/bin/pt-online-schema-change
+++ b/bin/pt-online-schema-change
@@ -4028,7 +4028,12 @@ sub set_dbh {
 
    my $sql = 'SELECT @@server_id /*!50038 , @@hostname*/, CONNECTION_ID() as connection_id';
    PTDEBUG && _d($dbh, $sql);
-   my ($server_id, $hostname, $connection_id) = $dbh->selectrow_array($sql);
+   # my ($server_id, $hostname, $connection_id) = $dbh->selectrow_array($sql);
+   # 因为OB的server_id是在binlog执行的， CONNECTION_ID()是在observer执行的，ODP无法在一个SQL语句中同时拿到这两个变量
+   # 所以需要分开拿这些变量
+   my $server_id = $dbh->selectrow_array('SELECT @@server_id');
+   my $hostname = $dbh->selectrow_array('SELECT @@hostname');
+   my $connection_id = $dbh->selectrow_array('SELECT CONNECTION_ID() as connection_id');
    PTDEBUG && _d($dbh, 'hostname:', $hostname, $server_id);
 
    if ( $self->{dbh} && $self->{dbh} == $dbh && $self->{dbh_set} && $self->{dbh_set} == $connection_id) {