more pictures can be found on my facebook profile (pic. are public available) .
If you like to dive in tenerife so I can suggest to visit Aqua-Marina. Great stuff available over there and they speak various languages - a multi-culti stuff is around there.
bought a new domain name: serializing.info
under this domain I would like to aggregate various information around serializing. if you have content which you would like to distribute here you're welcome to send me an email.
1. NAV
a. Net Asset Value
b. The value of the mutual –fund calculated daily (sometime more)
c. Total value of fund-dividend \ num of shares issued
2.OCIC
a. Open End Investment Company
b. A type of a mutual fund
3.SEC
a. Securities and Exchange Commission
4.IRA
a. Individual retirement Account
b. Allow to set 2K $ per year in MF without tax
5.ICI
a. Investment Company Institute
b. National association of Investment companies
6. Sector-Funds
a. A type of industry to invest in
b. Technology, biomedical, etc…
7. POP
a. Public Offering Price
b. When selling a MF
c. NAV + sales charge
8. Turnover
a. When a MF invests in securities, it sells and buys
these securities if a capital gain was achieved the
share holders of the MF will be taxed and will also
pay for the buying \ selling fees
b. Tot buy + sell \ 2 * fund total holdings
9. MF – FEES
a. Management fees
actual fees on managing the fund + administration
b. Non management fees
fees for other non managing parties like custodial,
accountant, board of directors, SEC registration
fee etc…
c. 12b-1 + non 12b-1 fees
12b1 – Marketing expenses of the fund according to the SEC rules
non 12b1 – other marketing not under SEC rules
d. Fees by the investor based on arrangements with the investor's broker
10. CDSL
a. Contingent Deferred Sales Load
11. TER
a. funds Total Expense Ratio
Disk I/O refers to the number of read and write operations performed by your
application on a physical disk or multiple disks installed in your server. Common
activities that can cause disk I/O-related bottlenecks include long-running file I/O
operations, data encryption and decryption, reading unnecessary data from database
tables, and a shortage of physical memory that leads to excessive paging activity.
Slow hard disks are another factor to consider.
To resolve disk-related bottlenecks:
- Start by removing any redundant disk I/O operations in your application.
- Identify whether your system has a shortage of physical memory, and,
if so, add more memory to avoid excessive paging.
- Identify whether you need to separate your data onto multiple disks.
- Consider upgrading to faster disks if you still have disk I/O
bottlenecks after doing all of above.
Configuration Overview
Microsoft Windows retrieves programs and data from disk. The disk
subsystem can be the most important aspect of I/O performance, but
problems can be masked by other factors, such as lack of memory.
Performance console disk counters are available within both the
LogicalDisk or PhysicalDisk objects.
Metrics
PhysicalDisk
- Avg. Disk Queue Length
- Avg. Disk Read Queue Length
- Avg. Disk Write Queue Length
- Avg. Disk sec/Read
- Avg. Disk sec/Transfer
- Disk Writes/sec
Tuning Options
If you determine that disk I/O is a bottleneck, you have a number of options:
- Defragment your disks. Use the Disk Defragmenter system tool.
- Use Diskpar.exe on Windows 2000 to reduce performance loss due to misaligned
disk tracks and sectors. You can use get the Diskpar.exe from the Windows 2000
Resource Kit.
- Use stripe sets to process I/O requests concurrently over multiple disks. The
type you use depends on your data-integrity requirements. If your applications
are read-intensive and require fault tolerance, consider a RAID 5 volume. Use
mirrored volumes for fault tolerance and good I/O performance overall. If you do
not require fault tolerance, implement stripe sets for fast reading and writing and
improved storage capacity. When stripe sets are used, disk utilization per disk
should fall due to distribution of work across the volumes, and overall throughput
should increase.
- If you find that there is no increased throughput when scaling to additional disks
in a stripe set, your system might be experiencing a bottleneck due to contention
between disks for the disk adapter. You might need to add an adapter to better
distribute the load.
- Place multiple drives on separate I/O buses, particularly if a disk has an
I/O-intensive workload.
- Distribute workload among multiple drives. Windows Clustering and
Distributed File System provide solutions for load balancing on different drives.
- Limit your use of file compression or encryption. File compression and
encryption are I/O-intensive operations. You should only use them where
absolutely necessary.
- Disable creation of short names. If you are not supporting MS-DOS for Windows
3.x clients, disable short names to improve performance. To disable short names,
change the default value of the \NtfsDisable8dot3NameCreation registry entry
(in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Filesystem) to 1.
- Disable last access update. By default, NTFS updates the date and time stamp
of the last access on directories whenever it traverses the directory. For a large
NTFS volume, this update process can slow performance. To disable automatic
updating, create a new REG_DWORD registry entry named
NtfsDisableLastAccessUpdate in HKEY_LOCAL_MACHINE\SYSTEM\CurrentContolSet\Control\Filesystem and set its value to 1.
Reserve appropriate space for the master file table. Add the
NtfsMftZoneReservation entry to the registry as a REG_DWORD in
HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet\Control \FileSystem.
When you add this entry to the registry, the system reserves space on the volume
for the master file table. Reserving space in this manner allows the master file
table to grow optimally. If your NTFS volumes generally contain relatively few
files that are large, set the value of this registry entry to 1 (the default).
- Typically you can use a value of 2 or 3 for moderate numbers of files, and use a value of 4 (the maximum) if your volumes tend to contain a relatively large number of files. However, make sure to test any settings greater than 2, because these greater values cause the system to reserve a much larger portion of the disk for the master file table.
- Use the most efficient disk systems available, including controller, I/O, cabling,
and disk. Use intelligent drivers that support interrupt moderation or interrupt
avoidance to alleviate the interrupt activity for the processor due to disk I/O.
- Check whether you are using the appropriate RAID configuration. Use RAID 10
(striping and mirroring) for best performance and fault tolerance. The tradeoff is
that using RAID 10 is expensive. Avoid using RAID 5 (parity) when you have
extensive write operations.
- Consider using database partitions. If you have a database bottleneck, consider
using database partitions and mapping disks to specific tables and transaction
logs. The primary purpose of partitions is to overcome disk bottlenecks for large
tables. If you have a table with large number of rows and you determine that it is
the source of a bottleneck, consider using partitions. For SQL Server, you can use
file groups to improve I/O performance. You can associate tables with file groups,
and then associate the file groups with a specific hard disk.
- Consider splitting files across hard disks. If you are dealing with extensive
file-related operations, consider splitting the files across a number of hard disks
to spread the I/O load across multiple disks.
Memory consists of physical and virtual memory. You need to consider how much memory is allocated to your application. When you evaluate memory-related bottlenecks, consider unnecessary allocations, inefficient clean up, and inappropriate caching and state management mechanisms. To resolve memory-related bottlenecks, optimize your code to eliminate these issues and then tune the amount of memory allocated to your application. If you determine during tuning that memory contention and excessive paging are occurring, you may need to add more physical memory to the server.
Low memory leads to increased paging where pages of your application’s virtual
address space are written to and from disk. If paging becomes excessive, page
thrashing occurs and intensive disk I/O decreases overall system performance.
Configuration Overview
Memory tuning consists of the following:
- Determine whether your application has a memory bottleneck. If
it has, then add more memory.
- Tune the amount of memory allocated if you can control the
allocation. For example, you can tune this for ASP.NET and
SQL Server.
- Tune the page file size.
Metrics
The performance counters help you identify memory bottlenecks. You should log these counter values to log files over a 24 hour period before you form any conclusions.
Memory
- Available MBytes
- Page Reads/sec
- Pages/sec
- Cache Bytes
- Cache Faults/sec
Server
- Pool Nonpaged Failures
- Pool Nonpaged Peak
Cache
- MDL Read Hits %
Bottlenecks
A low value of Available MBytes indicates that your system is low on physical
memory, caused either by system memory limitations or an application that is not
releasing memory. Monitor each process object’s working set counter. If Available
MBytes remains high even when the process is not active, it might indicate that the
object is not releasing memory. Use the CLR Profiler tool at this point to identify the source of any memory allocation problems. For more information, see “How To: Use
CLR Profiler” in the “How To” section of this guide.
A high value of Pages/sec indicates that your application does not have sufficient
memory. The average of Pages Input/sec divided by average of Page Reads/sec gives
the number of pages per disk read. This value should not generally exceed five pages
per second. A value greater than five pages per second indicates that the system is
spending too much time paging and requires more memory (assuming that the
application has been optimized).
Tuning Options
If you determine that your application has memory issues, your options include
adding more memory, stopping services that you do not require, and removing
unnecessary protocols and drivers. Tuning considerations include:
- Deciding when to add memory
- Page file optimization
Deciding When to Add Memory
To determine the impact of excessive paging on disk activity, multiply the values of
the Physical Disk\ Avg. Disk sec/Transfer and Memory\ Pages/sec counters. If the
product of these counters exceeds 0.1, paging is taking more than 10 percent of disk
access time. If this occurs over a long period, you probably need more memory. After
upgrading your system’s memory, measure and monitor again.
To save memory:
- Turn off services you do not use. Stopping services
that you do not use regularly saves memory and improves
system performance.
- Remove unnecessary protocols and drivers. Even idle
protocols use space in the paged and nonpaged memory
pools. Drivers also consume memory, so you should remove
unnecessary ones.
Page File Optimization
You should optimize the page file to improve the virtual memory performance of
your server. The combination of physical memory and the page file is called the
virtual memory of the system. When the system does not have enough physical
memory to execute a process, it uses the page file on disk as an extended memory
source. This approach slows performance.
To ensure an optimized page file:
- Increase the page file size on the system to 1.5 times
the size of physical memory available, but only to
a maximum of 4,095 MB. The page file needs to be at least
the size of the physical memory to allow the memory to be
written to the page file in the event of a system crash.
- Make sure that the page file is not fragmented on a given partition.
- Separate the data files and the page file to different
disks only if the disk is a bottleneck because of a lot
of I/O operation. These files should preferably be on the
same physical drive and the same logical partition. This
keeps the data files and the page file physically close to
each other and avoids the time spent seeking between two
different logical drives.
To configure the page file size
1. Open Control Panel.
2. Double-click the System icon.
3. Select the Advanced tab.
4. Click Performance Options.
5. Click Change. The Virtual Memory dialog box appears
6. Enter new values for Initial size and Maximum size. Click Set, and then click OK.
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