l*****k
发帖数: 587 | 1 I tried to connect to a oracle 8 db in sql:
connect system/manager@blabal as sysdba;
always get feedback like
ORA-01031: insufficient privileges
don't know why, and,which user can use exp80 in oracle 8?
Thanks, I am new in this, thanks again |
|
z****e
发帖数: 17 | 2 当我使用MS SQL Enterprise Manager,能够看到SQL Server正在运行,灯是绿色的,但是当
在SQL Server的名字上点击时,等了一会儿,弹出一个错误窗口来,显示类似如下:
A connection could not be established to 'servername'-[DB-library]Unable to
connect. SQL Server is unavailable or does not exist. General network error.
Check your documentation
我检查了,MSSQLServer和SQLExecutive.EXE都在后台运行,而且前台的程序都可以正确地
与SQL Server连接,读写数据库.
但是我没法在SQL SERVER上进行管理.环境是:Windows NT 4 Server + service pack 6 +
MS SQL Server 6.5, 没有其他的服务程序.
都谢了! |
|
f*c
发帖数: 7 | 3 I am now trying to connect Access 2002 mdb file from VB 6.0, but i found that
VB doesn't recognize this file, i use Access 2002 to convert it to Access 97
format, then VB recognized it, but does anybody know the way to connect with
Access 2002 from VB 6.0 directly? thank you for your help! |
|
l*****k
发帖数: 587 | 4 in dbi, I can only view by connect as owner of the table. Another
db user I only granted "select" previlidge, when try to connect as
that user, it keeps telling me "table or view not exist"
my code:
select * from patient_tab
I also tried to add schema
select * from core.patient_tab
Thanks |
|
G**T
发帖数: 388 | 5 【 以下文字转载自 Programming 讨论区,原文如下 】
发信人: GTGT (玩), 信区: Programming
标 题: connect mysql remotely
发信站: Unknown Space - 未名空间 (Fri Dec 3 13:01:51 2004) WWW-POST
I have a website which is hosted remotely. On the host, there is a mysql
database. The website is using the database without any problems. Now, I want
to connect the mysql database remotely from my local machine (at home). My
question is: this should be ok, or it really depends on the hosting whether
hosting let me do so?
My situation is:
the |
|
t*********i
发帖数: 217 | 6 I am not a developer. But is there anything missing in the question?
connection life time? # of connections to increase and decrease? |
|
z***y
发帖数: 7151 | 7 I was called from one company who get my number from my previous client.
They
have an issue to connect their sql server instance remotely. While I'm
driving I told them to run a tool called PortQry from Microsoft website. I
told them you can find root cause right away. However they insisted to ask
me
to do the troubleshooting. I had to stop at road side then. It took me 5
minutes to solve their issue. Three minutes were spent on connecting to
their
gotomeeting.
Anyway, this tool is very useful... 阅读全帖 |
|
D********g
发帖数: 650 | 8 stack trace 如下：
SQL ERROR:Sql server generic error (internal) 4!Connection reset;sql state:
08S01;stacktrace: com.microsoft.sqlserver.jdbc.SQLServerException:
Connection reset at com.microsoft.sqlserver.jdbc.SQLServerConnection.
terminate(SQLServerConnection.java:1352) at com.microsoft.sqlserver.jdbc.
SQLServerConnection.terminate(SQLServerConnection.java:1339) at com.
microsoft.sqlserver.jdbc.TDSChannel.read(IOBuffer.java:1654) at com.
microsoft.sqlserver.jdbc. |
|
f*****e
发帖数: 5177 | 9 一个小系统。以前用的是XP + Sqlserver 2000 personal。Sqlserver 2000 personal
限制10 concurrent conenction。现在换成XP + Sqlserver 2008 standard，现在可以
支持多少个connection？Sqlserver的限制应该没有了。但是不知道XP有没有
connection的限制。 |
|
f*****e
发帖数: 5177 | 10 我前面说了sqlserver本身没有限制。
但是我不知道装在XP上，XP对TCP的限制对sqlserver会不会有影响。
我的理解是xP的那个是限制并发outbound tcp connection。
sqlserver应该主要是inbound connection。
所以应该没有问题。
不知道理解的对不对。 |
|
n****e
发帖数: 1403 | 11 在做data migration
从一个database向另外一个远程的database在导，为什么还是会connection lost，已
经把远程的firewall设成TCP inactivity time out 为 １４４０ minutes（一天），
但是还是会大概在３小时后connection lost？
是不是数据库还有什么设置？ |
|
s********e
发帖数: 21 | 12 Any expert is familiar with VoD service operation? Like YouTube.com, so many
people are watching videos at the same time. What kind of hardware and
network connection is required to support such heavy-traffic video streaming
? Arrays of streaming servers connected to T3 backbones? (and many edge
servers for sure) |
|
k**********i
发帖数: 177 | 13 P1i, but it can not connect the WPA model wireless network.
Everytime it connects, it needs a WEP key.
So how to deal with it? |
|
s*****w
发帖数: 1527 | 14 【 以下文字转载自 Software 讨论区 】
发信人: somehow (要像蟑螂一样的坚强), 信区: Software
标 题: VPN question: without router it connects, with route it's not
发信站: BBS 未名空间站 (Wed May 5 13:38:24 2010, 美东)
basically when connection to office using VPN,
it doesn't work after the router.
i do have the VPN (different vpn client) working when was in the last
company.
what should i change in the setting, thanks ! |
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f*******8
发帖数: 3612 | 15 we have two switch with 4 SFP port(WS-C3560-48PS-S, 48 10/100 PoE + 4 SFP IP
Base Image)
located at two floors to be connected.(distance is less than 100 meters)
should I use the SFP port to connect them?
how to make the optical cable? or do I need a converter?
how much it cost?
xiexie le. |
|
s******v
发帖数: 4495 | 16 总结
1. Netflix Open Connect是NFLX自己基于开源和off-shelf硬件而开发的一个CDN系统
2. 有两种CDN实现模式，
1) ISP从NFLX拿到OCA，建立BGP链接，作为Local Stream Server，具体的看下面
control flow;
2) NFLX在大的Internet Exchange里面建立Local CDN cluster, 和ISP直接链接
NFLX占了非常高的Internet traffic比例, 2H 2013 vs 2H 2012
1) NFLX 32% ~ 33%
2) Youtube 18% ~ 14%
Netflix decrease illegal file sharing.
项目的背景：
1）项目从2011年开始，目前已经offload了100%的Traffic，达到了16TB；而其他的CDN
例如，Akamai，Limenetwork，Level 3只能达到20-25%；
2）4个Racks的数据量可以达到8.6PB
3）multiple-tier arch:
3.1) Headend, 1(6?) OCA... 阅读全帖 |
|
r*******u
发帖数: 156 | 17 I have a 8' netbook with wireless internet connection. I wish to connect my
desktop PC (without wireless adaptor) to this netbook so that I can go
internet online through this netboob. Because desktop PC has a much better
monitor.
Is it possible? I am not familiar with computer. Any information will be
appreciated. |
|
d*****r
发帖数: 57 | 18 Not familiar with Windows ME. I guess it might have sth to do the IP
configuration for your PC and router. While you connect with cable modem, IP
of your PC should be set to the public IP provided by Roadrunner. If you are
connecting through router, your IP should be either private (192.168.0.*) or
from DHCP, depending on configuration of router.
BTW, what do you mean everything is OK for your roommate? Is (s)he able to
switch back and forward from modem and router w/o changing any configuration |
|
e*******e
发帖数: 987 | 19 I ordered directTV DSL service to connect my linux RedHat 7.3 server to the
internet. I chose directTV DSL because they give a dynamic IP so I can host a
website on the linux server.
I followed the instructions to set up the hardware. The last step is to browse
to an internal website and do the rest of the configuration. But I don't have
X window or a browser on the linux machine. So i cannot do the last step (
configure the TCP/IP settings, i guess). Then I connected my windows machine
to the D |
|
q**u
发帖数: 12289 | 20 The easiest way to connect just two laptops is via a cross-over cable. If you
want to share a broadband connection, get a broadband router. If your router
doesn't have a built-in switch, then you will need either a hub or a switch.
But we are talking about a "network hub", NOT a "USB hub"!
between
hubs |
|
m*******g
发帖数: 31 | 21 Hi All,
The laoptop I borrowed really made me flat, I mean, the internet connection.
Once plug-in cable, the icon shows up but I never can the inertnet, and when I
right-click on the local connection(said 100.0mps), there seeems be a huge
number of sent packages, but 0 package received. Could anybody please help me
out this? It is a WinXP machine.
Thanks! |
|
G******s
发帖数: 1530 | 22 My desktop suddenly could not connect to the internet anymore. But the
network status shows "connected. firewalled." Everything used to be OK
yesterday.
I restarted the computer, still the same problem. Did anyone meet simila
r problem before? Anything I can do about it? Thank you so much. |
|
s*******l
发帖数: 35 | 23 My server is RCN (www.rcn.com) 我今天早晨7点多上网时，伴随着一声巨大的雷声，
internet connection 突然中断了，（可能是碰巧，应该是这个没关系），之后一直连
不上，重新启动也不行，打电话给rcn，他们让我unplug everything, and
reconnect everything after 60 seconds, 我试了好几次都不行，the cable light
and power light are on, so the cable connection should be fine, 但是电脑右下
角却显示a network cable is unplugged, PC light and Data light keep flashing,
（以前好像就是这样，刚用rcn几天，没怎么留意）。是modem到PC之间的问题吗？我
试了换了条internet cord，还是不行（但是也没理由，崭新的网线，以前都用得好好
的）rcn的人又说什么security可能expire，the block my computer t |
|
l******e
发帖数: 956 | 24 I'm using Comcast at home. Recently I lost connection frequently. The
connection will recover after awhile and I don't need do anything, but
sometimes it will drop again in very short time. It happens most in morning.
Anybody gets the same problem?
Thanks. |
|
b****3
发帖数: 37 | 25 Hello everyone,
There is one problem when I connect to the university LAN. The message
says limited connection(to LAN). Does anyone know why this happen? I use
Vista on HP laptop.When I moved to the lab and the laptop works wells. It
only does not work at my apartment.
Thank you. |
|
B******N
发帖数: 445 | 26 first：pay attention that rs.getInt(column_number), the column_number is one
based not zero based.
second：
replace:
DriverManager.registerDriver(new SQLServerDriver());
Connection conn = DriverManager.createConnection(sql, "sa", "sa");
with this:
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
Connection conn = DriverManager.getConnection(sql, "sa", "sa"); |
|
g*****g
发帖数: 34805 | 27 Check if your OS has TCP connection limit, check if your server can
handle that many simultaneous connections, then you can check tomcat
parameters like maxThreads
"
server? |
|
l*****b
发帖数: 82 | 28 Hi, goodbug, thank you. Could you advise where to check OS TCP connection
setting and Tomcat config file for connection? |
|
h**********c
发帖数: 4120 | 29 the question:
Sun has a jdbc pool example. I implement the interfaces.
The connections time out overnight.
It is not recommended to use auto-reconnect. why? the key point is I don't
know how to set auto-reconnect.
Or there is better solution.
Put simple,
how to check java.sql.connection valid? It is has abstract function isValid,
but how to overwrite it? if not valid, how to reconnect?
Thanks in advance. |
|
d**k
发帖数: 1223 | 30 最近要求改了，原来用来做authentication的ldap要求用ssl connection. 巨土的是怎
么也连不上。用ldap browser都没有问题，到了code里就是不行。我用的是ldapjdk的
package, 就下面几行code....
String dn="cn=testUser,ou=services,dc=myDomin,dc=org";
String password="ldapSvc";
java.security.Security.addProvider(new
com.sun.net.ssl.internal.ssl.Provider());
netscape.ldap.factory.JSSESocketFactory skt_fctry =
new
netscape.ldap.factory.JSSESocketFactory(null);
... 阅读全帖 |
|
e*****t
发帖数: 1005 | 31 session? or you really mean connection?
The connection object can be accessed from different threads for sure. But
when you are talking about transaction, you have to check what transaction
management you are using. |
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T*******x
发帖数: 8565 | 32 比如在一个函数内部，connection是一个local variable。
函数结束的时候为什么不自动释放jdbc connection？
做不到吗？内部有什么难度吗？ |
|
g*****g
发帖数: 34805 | 33 OK, you are probably right. I haven't done raw jdbc in years. Application
server always use a connection pool and you don't really want to open a
connection every time. |
|
w**z
发帖数: 8232 | 34 connection pool implements close() method, it will put the connection back
to the pool. But for sure, caller needs to close ResultSet and Statement. |
|
T*******x
发帖数: 8565 | 35 也需要connection.close()才能put connection back to pool吧？ |
|
w**z
发帖数: 8232 | 36 the connection pool implementation overrides the close method , if you call
close on the connection, it will be put back to the pool. |
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t*****s
发帖数: 124 | 37 谨慎怀疑还是有connection没有close掉吧
因为一般driver的实现在close connection时，
会自动close相关连的statement和resultset
当然，手动close相关的statement和resultset是良好的编程习惯
很想知道楼主用的是什么样的driver
memory
整个 |
|
c***c
发帖数: 6234 | 38 统一谢谢各位了。
是的，用connection pool，如果是conn.close()，就是放回pooling。如果statement
或 resultset 没有close，conn是不会没其request用的。
争取了2 周，彻底fix这个。
难道不能有办法强行关掉所有statement 和resultset在本connection里吗？
以前用c#没这么大问题。
再次感谢回复 |
|
t**********y
发帖数: 374 | 39 May I use "Remote Desktop Connection" from windows to connect to my linux
server?
I generally use putty. Just wondering if this offers another option. Thanks. |
|
j*******d
发帖数: 8834 | 40 doh ! ping is ICMP and connect(2) is @ TCP layer......
did connect(2) return right away or it took a couple of seconds? |
|
S*A
发帖数: 7142 | 41 C10M 的定义有好几个方面，不是 hold 住 10M 个连接没有神魔
流量就可以的。
这个是网上抄来的 C10M 定义：
Today (2013), $1200 will buy you a computer with 8 cores, 64 gigabytes of
RAM, 10-gbps Ethernet, and a solid state drive. Such systems should be able
to handle:
- 10 million concurrent connections
- 10 gigabits/second
- 10 million packets/second
- 10 microsecond latency
- 10 microsecond jitter
- 1 million connections/second
直接用 linux 做的网络处理上限大概在 1M packet/sec 左右。
所以没有 openonload/DPDK 包的数目就吃不消。 |
|
d*******r
发帖数: 3299 | 42 这个是我没说清楚，我说的匀速是指一条从client到server的connection以内，比如游
戏人物到server的 heartbeats 或者 每单位时间的 游戏client 的 states update.
我觉得这种 scenario, 每个状态更新的packet，都是大小差不多的，small size的。
不会一个很大，一个很小。所以 message or packets per second 的 measurement 对
这种 scenario 是有意义的。
但是从 server 端看，肯定也有忽然接收很多 concurrent connections 的情况，比如
周五晚上大家都上线玩游戏了。 |
|
g*****g
发帖数: 34805 | 43 这只能说明你没有实际经验。能处理10M， 再多处理1M，从容量本身看是不难。
但是你忘了，前面这10M的连接是慢慢产生的，大多数时候这些连接只有heartbeat, 没
有信息交换。
但一旦有机器当机，这1M的重新连接请求是同时到来的，伴随的是需要重新产生用户
session, 要读DB, 要计算，
会产生巨大的冲击。这个冲击远远大于10M大多idle的连接。你的机器是顶不住的。
你说的要能够处理几倍的容量同样不对，一般的做法就是跑在50％－70%，超过了动态
继续起VM。
而不是预留几倍的处理能力。这本来就是云计算的长处。
persistent connection跟stateless connection在failover设计里是有很大区别的。
前者需要更大的余量。
用100台1M和10台10M的区别是巨大的。没有真正搞过实际系统的人不会想到这些问题，
但不等于这些问题就不存在了。
我说是伪命题，就是因为世界上100M 在线的系统屈指可数，而且据我所知没有一个是
用10台机器的，几百个上千个VM才是惯例。将来如果有1000M的系统，同样会倾向于多
起VM,
而不是多压榨单机性能。篮... 阅读全帖 |
|
S*A
发帖数: 7142 | 44 C10M 的定义有好几个方面，不是 hold 住 10M 个连接没有神魔
流量就可以的。
这个是网上抄来的 C10M 定义：
Today (2013), $1200 will buy you a computer with 8 cores, 64 gigabytes of
RAM, 10-gbps Ethernet, and a solid state drive. Such systems should be able
to handle:
- 10 million concurrent connections
- 10 gigabits/second
- 10 million packets/second
- 10 microsecond latency
- 10 microsecond jitter
- 1 million connections/second
直接用 linux 做的网络处理上限大概在 1M packet/sec 左右。
所以没有 openonload/DPDK 包的数目就吃不消。 |
|
d*******r
发帖数: 3299 | 45 这个是我没说清楚，我说的匀速是指一条从client到server的connection以内，比如游
戏人物到server的 heartbeats 或者 每单位时间的 游戏client 的 states update.
我觉得这种 scenario, 每个状态更新的packet，都是大小差不多的，small size的。
不会一个很大，一个很小。所以 message or packets per second 的 measurement 对
这种 scenario 是有意义的。
但是从 server 端看，肯定也有忽然接收很多 concurrent connections 的情况，比如
周五晚上大家都上线玩游戏了。 |
|
