Specifying this seems to reslove the problem:
-Xmx512m -XX:MaxPermSize=512m
When stress testing our loadbalancer, i was unable to get more than 20 reliable ssh connections. The following error would be reported.
ssh_exchange_identification: Connection closed by remote host
The resolution for this is quite simple.
Edit the /etc/ssh/sshd_config file and increase the MaxStartups. On my server i set this to 200.
Edit /etc/sysctrl.conf and add the following line:
net.core.netdev_max_backlog = 3000
Then apply this change:
# sysctl -p
The Openfiler NAS/SAN Appliance (NSA) is a Storage Management Operating System / NAS Appliance distribution. It is powered by the Linux 2.6 kernel and Open Source applications such as Apache, Samba, LVM2, ext3, Linux NFS and iSCSI Enterprise Target. Openfiler combines these ubiquitous technologies into a small, easy to manage solution fronted by a powerful web-based management interface. Openfiler allows you to build a Network Attached Storage (NAS) and/or Storage Area Network (SAN) appliance, using industry-standard hardware, in less than 10 minutes of installation time.
Building upon the popularity of server virtualization technologies such as VMware, Virtual Iron, and Xen, Openfiler can also be deployed as a virtual machine instance or on a bare metal machine.
This deployment flexibility of Openfiler ensures that storage administrators are able to make the best use of system performance and storage capacity resources when allocating and managing networked storage in a multi-platform environment.
Openfiler is ideally suited for use with High Availability Recital applications as it incorporates:
- Heartbeat cluster manager
- drbd disk replication
- CIFS
- NFS
- Software and hardware RAID
- FTP
- rsync
- HTTP/DAV
- iSCSI
- LVM2
- Multiple NIC bonding for High Availability
- Powerful web-based GUI
A quick tip for optimizing TCP performance on linux.
edit /etc/sysctl.conf add the lines:
If using gigabit ethernet:
net.ipv4.tcp_mem= 98304 131072 196608
net.ipv4.tcp_window_scaling=1
net.core.wmem_default = 65536
net.core.rmem_default = 65536
net.core.wmem_max=8388608
To reload these use:
# sysctl -p
If using infiniband:
net.ipv4.tcp_window_scaling=1
net.ipv4.tcp_timestamps=0
net.ipv4.tcp_sack=0
net.ipv4.tcp_rmem=10000000 10000000 10000000
net.ipv4.tcp_wmem=10000000 10000000 10000000
net.ipv4.tcp_mem=10000000 10000000 10000000
net.core.rmem_max=524287
net.core.wmem_max=524287
net.core.rmem_default=524287
net.core.wmem_default=524287
net.core.optmem_max=524287
net.core.netdev_max_backlog=300000
Another useful article on IBM developerworks shows how to build PHP extensions using SWIG. You can find the article here.
If you want details about how storage devices are performing on Redhat/Centos/Fedora use the vmstat and iostat commands.
After installing Centos 5.3 the iostat command is not available. To install it use yum:
# yum install sysstat
For systems that do not have the xterm libraries installed, please install these to use xterm, or set the DB_TERM environment variable to start Recital from a terminal:
DB_TERM=gnome-terminal; export DB_TERM
This setting can be added to the /opt/recital/conf/recital.conf (text) file to make it available system-wide.
Please note that the Recital ODBC Driver for Linux requires a 32 bit ODBC Driver Manager.
Centos 6:
sudo yum install zlib-devel.i686 pam-devel.i686(and accept dependencies)
Then run the installer in text mode
sudo ./recital-10.0.3-linux32.bin --mode textRun Recital with sudo the first time, to set the system filetype compatiblity settings.
sudo recitalAfter saving the compatibility settings, quit to exit, then run Recital as your preferred user.
> quit
$ recital
RedHat / Fedora family:
sudo yum install zlib-devel.i686 pam.i686(and accept dependencies)
Then run the installer in text mode
sudo ./recital-10.0.3-linux32.bin --mode textRun Recital with sudo the first time, to set the system filetype compatiblity settings.
sudo recitalAfter saving the compatibility settings, quit to exit, then run Recital as your preferred user.
> quit
$ recital
Ubuntu family:
sudo apt-get install ia32-libsIn later versions of Ubuntu, ia32-libs is obsolete. The following package should be installed:
sudo apt-get install lib32z1Ubuntu 12.04 and above also require the following:
sudo apt-get install libpam0g:i386Then run the installer in text mode
sudo ./recital-10.0.3-linux32.bin --mode textRun Recital with sudo the first time, to set the system filetype compatiblity settings.
sudo recitalAfter saving the compatibility settings, quit to exit, then run Recital as your preferred user.
> quit
$ recital
System Requirements:
- Minimum memory: 4MB
- Minimum Diskspace: ~20MB
On entry to the .rsp page.
IF type( _session["state"] ) != "U"m_state = _session["state"]RESTORE DATASESSION FROM m_state
ELSE
// open up your tables for the first timeENDIF
SAVE DATASESSION TO m_state_SESSION["state"] = m_state
Recital is a dynamic programming language with an integrated high performance database particularly well suited for the development and deployment of high transaction throughput applications. Recital 10 further enhances Recital with extensive features and functionality to facilitate its use in fault tolerant high availability systems. Much of the development of Recital 10 was concentrated on performance optimizations and cluster aware functionality to provide an application platform that can be scaled as needed without any application changes.
Key features of Recital 10 include:
- Cluster aware database engine that works transparently with drbd, heartbeat, glusterfs and samba
- High degree of fault tolerance with self healing indexes
- Massive performance improvements
- Extensive internals overall and modernization with superior object-oriented capabilities
- Chronological data versioning with database timelines
- SmartQuery caching
- Database Administration Tools
- Code and Data Profiling
- Better integration with unix/linux command shell
- Incorporates a range of new built-in functions compatible with those in the PHP core libraries
- Built-in support for outputting data in HTML, XML, and JSON format
- Seamless SQL command integration into the Recital scripting language
- Much improved Microsoft FoxPRO language compatibility
- Numerous extensions and improvements (see below for details)
- Very large file support (2^63)