Bug #32223 SETting max_allowed_packet variable

      
Inconsistent behavior of session variable max_allowed_packet 
(and net_buffer_length); only assignment to the global variable 
has any effect, without this being obvious to the user.
      
The patch for Bug#22891 is backported to 5.0, making the two
session variables read-only. As this is a backport to GA 
software, the error used when trying to assign to the read-
only variable is ER_UNKNOWN_ERROR. The error message is the 
same as in 5.1+.

6 files changed, 48 insertions, 45 deletions

diff --git a/mysql-test/r/func_compress.result b/mysql-test/r/func_compress.result
index d8745c38f57..d0689af5bff 100644
--- a/mysql-test/r/func_compress.result
+++ b/mysql-test/r/func_compress.result
@@ -68,7 +68,7 @@ Warnings:
 Error	1259	ZLIB: Input data corrupted
 Error	1256	Uncompressed data size too large; the maximum size is 1048576 (probably, length of uncompressed data was corrupted)
 drop table t1;
-set @@max_allowed_packet=1048576*100;
+set @@global.max_allowed_packet=1048576*100;
 select compress(repeat('aaaaaaaaaa', IF(XXX, 10, 10000000))) is null;
 compress(repeat('aaaaaaaaaa', IF(XXX, 10, 10000000))) is null
 0
diff --git a/mysql-test/r/packet.result b/mysql-test/r/packet.result
index 5cc63c4690d..ecbb47d4ee0 100644
--- a/mysql-test/r/packet.result
+++ b/mysql-test/r/packet.result
@@ -3,32 +3,22 @@ set @net_buffer_length=@@global.net_buffer_length;
 set global max_allowed_packet=100;
 Warnings:
 Warning	1292	Truncated incorrect max_allowed_packet value: '100'
-set max_allowed_packet=100;
-Warnings:
-Warning	1292	Truncated incorrect max_allowed_packet value: '100'
 set global net_buffer_length=100;
 Warnings:
 Warning	1292	Truncated incorrect net_buffer_length value: '100'
-set net_buffer_length=100;
-Warnings:
-Warning	1292	Truncated incorrect net_buffer_length value: '100'
 SELECT length("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa") as len;
 len
 1024
 select repeat('a',2000);
 repeat('a',2000)
-NULL
-Warnings:
-Warning	1301	Result of repeat() was larger than max_allowed_packet (1024) - truncated
+aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 select @@net_buffer_length, @@max_allowed_packet;
 @@net_buffer_length	@@max_allowed_packet
 1024	1024
 SELECT length("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa") as len;
 ERROR 08S01: Got a packet bigger than 'max_allowed_packet' bytes
 set global max_allowed_packet=default;
-set max_allowed_packet=default;
 set global net_buffer_length=default;
-set net_buffer_length=default;
 SELECT length("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa") as len;
 len
 100
diff --git a/mysql-test/r/variables.result b/mysql-test/r/variables.result
index fbec38c9a9f..496f0b69fb8 100644
--- a/mysql-test/r/variables.result
+++ b/mysql-test/r/variables.result
@@ -187,7 +187,7 @@ Variable_name	Value
 myisam_max_sort_file_size	FILE_SIZE
 set global net_retry_count=10, session net_retry_count=10;
 set global net_buffer_length=1024, net_write_timeout=200, net_read_timeout=300;
-set session net_buffer_length=2048, net_write_timeout=500, net_read_timeout=600;
+set session net_write_timeout=500, net_read_timeout=600;
 show global variables like 'net_%';
 Variable_name	Value
 net_buffer_length	1024
@@ -196,35 +196,39 @@ net_retry_count	10
 net_write_timeout	200
 show session variables like 'net_%';
 Variable_name	Value
-net_buffer_length	2048
+net_buffer_length	16384
 net_read_timeout	600
 net_retry_count	10
 net_write_timeout	500
-set session net_buffer_length=8000, global net_read_timeout=900, net_write_timeout=1000;
+set global net_buffer_length=8000, net_read_timeout=900, net_write_timeout=1000;
 show global variables like 'net_%';
 Variable_name	Value
-net_buffer_length	1024
+net_buffer_length	7168
 net_read_timeout	900
 net_retry_count	10
 net_write_timeout	1000
 show session variables like 'net_%';
 Variable_name	Value
-net_buffer_length	7168
+net_buffer_length	16384
 net_read_timeout	600
 net_retry_count	10
 net_write_timeout	500
-set net_buffer_length=1;
+set global net_buffer_length=1;
 Warnings:
 Warning	1292	Truncated incorrect net_buffer_length value: '1'
-show variables like 'net_buffer_length';
+show global variables like 'net_buffer_length';
 Variable_name	Value
 net_buffer_length	1024
-set net_buffer_length=2000000000;
+set global net_buffer_length=2000000000;
 Warnings:
 Warning	1292	Truncated incorrect net_buffer_length value: '2000000000'
-show variables like 'net_buffer_length';
+show global variables like 'net_buffer_length';
 Variable_name	Value
 net_buffer_length	1048576
+set session net_buffer_length=1024;
+ERROR HY000: SESSION variable net_buffer_length is read-only. Use SET GLOBAL net_buffer_length to assign the value
+set session max_allowed_packet=1024;
+ERROR HY000: SESSION variable max_allowed_packet is read-only. Use SET GLOBAL max_allowed_packet to assign the value
 set character set cp1251_koi8;
 show variables like "character_set_client";
 Variable_name	Value
@@ -393,7 +397,7 @@ set last_insert_id=1;
 set global local_infile=1;
 set long_query_time=100;
 set low_priority_updates=1;
-set max_allowed_packet=100;
+set global max_allowed_packet=100;
 Warnings:
 Warning	1292	Truncated incorrect max_allowed_packet value: '100'
 set global max_binlog_cache_size=100;
@@ -417,7 +421,7 @@ select @@max_user_connections;
 100
 set global max_write_lock_count=100;
 set myisam_sort_buffer_size=100;
-set net_buffer_length=100;
+set global net_buffer_length=100;
 Warnings:
 Warning	1292	Truncated incorrect net_buffer_length value: '100'
 set net_read_timeout=100;
diff --git a/mysql-test/t/func_compress.test b/mysql-test/t/func_compress.test
index c84f22c5595..2ee222c6a10 100644
--- a/mysql-test/t/func_compress.test
+++ b/mysql-test/t/func_compress.test
@@ -43,8 +43,10 @@ drop table t1;
 # note that when LOW_MEMORY is set the "test" below is meaningless
 #
 
-set @@max_allowed_packet=1048576*100;
+set @@global.max_allowed_packet=1048576*100;
 --replace_result "''" XXX "'1'" XXX
+# reconnect to make the new max packet size take effect
+--connect (newconn, localhost, root,,)
 eval select compress(repeat('aaaaaaaaaa', IF('$LOW_MEMORY', 10, 10000000))) is null;
 
 #
diff --git a/mysql-test/t/packet.test b/mysql-test/t/packet.test
index 6210e9986ad..7e08a0f6c3f 100644
--- a/mysql-test/t/packet.test
+++ b/mysql-test/t/packet.test
@@ -15,31 +15,33 @@
 set @max_allowed_packet=@@global.max_allowed_packet;
 set @net_buffer_length=@@global.net_buffer_length;
 
-connect (con1,localhost,root,,);
-connection con1;
+
+# setting values below minimum threshold of 1024 will cause truncating
 set global max_allowed_packet=100;
-set max_allowed_packet=100;
 set global net_buffer_length=100;
-set net_buffer_length=100;
-# Have to be > 1024 as min value of net_buffer_length is 1024
+
+# is not yet in effect
 SELECT length("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa") as len;
-# Should return NULL as 2000 is bigger than max_allowed_packet
 select repeat('a',2000);
-connection default;
-disconnect con1;
 
 #
-# Connection 2 should get error for too big packets
+# Connection 1 should get error for too big packets
 #
-connect (con2,localhost,root,,);
-connection con2;
+connect (con1,localhost,root,,);
+connection con1;
 select @@net_buffer_length, @@max_allowed_packet;
 --error ER_NET_PACKET_TOO_LARGE
 SELECT length("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa") as len;
+connection default;
+disconnect con1;
+
+#
+# Reset to default values and reconnect
+#
 set global max_allowed_packet=default;
-set max_allowed_packet=default;
 set global net_buffer_length=default;
-set net_buffer_length=default;
+connect (con2,localhost,root,,);
+connection con2;
 SELECT length("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa") as len;
 select length(repeat('a',2000));
 connection default;
diff --git a/mysql-test/t/variables.test b/mysql-test/t/variables.test
index 424776dfda4..91f75cf6cd4 100644
--- a/mysql-test/t/variables.test
+++ b/mysql-test/t/variables.test
@@ -131,17 +131,22 @@ show global variables like 'myisam_max_sort_file_size';
 
 set global net_retry_count=10, session net_retry_count=10;
 set global net_buffer_length=1024, net_write_timeout=200, net_read_timeout=300;
-set session net_buffer_length=2048, net_write_timeout=500, net_read_timeout=600;
+set session net_write_timeout=500, net_read_timeout=600;
 show global variables like 'net_%';
 show session variables like 'net_%';
-set session net_buffer_length=8000, global net_read_timeout=900, net_write_timeout=1000;
+set global net_buffer_length=8000, net_read_timeout=900, net_write_timeout=1000;
 show global variables like 'net_%';
 show session variables like 'net_%';
-set net_buffer_length=1;
-show variables like 'net_buffer_length';
+set global net_buffer_length=1;
+show global variables like 'net_buffer_length';
 #warning 1292
-set net_buffer_length=2000000000;
-show variables like 'net_buffer_length';
+set global net_buffer_length=2000000000;
+show global variables like 'net_buffer_length';
+
+--error ER_UNKNOWN_ERROR
+set session net_buffer_length=1024;
+--error ER_UNKNOWN_ERROR
+set session max_allowed_packet=1024;
 
 set character set cp1251_koi8;
 show variables like "character_set_client";
@@ -272,7 +277,7 @@ set last_insert_id=1;
 set global local_infile=1;
 set long_query_time=100;
 set low_priority_updates=1;
-set max_allowed_packet=100;
+set global max_allowed_packet=100;
 set global max_binlog_cache_size=100;
 set global max_binlog_size=100;
 set global max_connect_errors=100;
@@ -286,7 +291,7 @@ set global max_user_connections=100;
 select @@max_user_connections;
 set global max_write_lock_count=100;
 set myisam_sort_buffer_size=100;
-set net_buffer_length=100;
+set global net_buffer_length=100;
 set net_read_timeout=100;
 set net_write_timeout=100;
 set global query_cache_limit=100;